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Katsumi Aida - One of the best experts on this subject based on the ideXlab platform.
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Effects of growth hormone and cortisol on the downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
General and comparative endocrinology, 2006Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of ovine growth hormone (oGH) and cortisol on downstream Migratory Behavior in yearling (1 + ) smolts and underyearling (0 + ) parr of masu salmon, Oncorhynchus masou , were examined during the downstream Migratory period in spring using artificial raceways. In May, each of 22 1 + smolts and 0 + parr were implanted with cholesterol pellets containing 250 μg of oGH and/or 2 mg of cortisol. Their downstream Migratory Behavior was subsequently observed in artificial raceways, along with control groups 4–23 days after implantation. In 1 + smolts, the frequency of downstream Migratory Behavior was 23%, 18%, 72%, and 82% in the control, oGH, cortisol, and oGH + cortisol-treated groups, respectively. The frequency was significantly higher in the cortisol and oGH + cortisol-treated groups than in the control and oGH-treated groups. In 0 + parr, the frequency of downstream Migratory Behavior in the cortisol (82%) and cortisol + oGH-treated (90%) groups was significantly higher than in the control (18%) and oGH-treated (0%) groups. These results indicate that cortisol is an important endocrine factor inducing downstream Migratory Behavior in both 1 + smolt and 0 + parr of masu salmon.
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Effects of Low pH on Upstream Migratory Behavior in Land-Locked Sockeye Salmon Oncorhynchus nerka
Water Air and Soil Pollution, 2001Co-Authors: Kazumasa Ikuta, Arimune Munakata, Masafumi Amano, Katsumi Aida, Shoji KitamuraAbstract:The effects of low pH on upstream Migratory Behavior in land-locked sockeye salmon Oncorhynchus nerka were examined using 2-way flow-through channels. Homing mature salmon captured at the mouth of their native stream were used. When neutral (pH 6.7) hatchery water of the same origin as native stream water was allowed to flow through both channels, fish showed active swimming into both channels during a 48 hrs period. When water pH in one channel was lowered by the addition of sulfuric acid, salmon completely ceased upstream swimming Behavior into areas of pH lower than 6.0, and swam up into only neutral areas. In the lower pond of the 2-way channels, fish also avoided acidic areas even when average pH was 6.2. Since it has been reported that extremely slight changes in pH such as in the pH 6 range inhibits spawning Behavior in this species, it is suggested that land-locked sockeye salmon have a sensitive ability to perceive even slight acidity, and avoid environments which may be deleterious to their offspring.
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the effects of testosterone on upstream Migratory Behavior in masu salmon oncorhynchus masou
General and Comparative Endocrinology, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract Effects of testosterone (T) on upstream Migratory Behavior in masu salmon, Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 μg of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream Migratory Behavior of yearling immature parr implanted with a capsule containing T 500 μg or vehicle was observed from September through November. In Experiment 3, upstream Migratory Behavior of castrated, castrated + T 50 μg, castrated + T 500 μg, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream Migratory Behavior of the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T 4 ), and triiodothyronine (T 3 ) by radioimmunoassay. Administration of T caused increases in plasma T levels within the physiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 μg, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 μg and sham-operated groups than in the castrated group. In Experiment 2, the frequency was higher in T 500 μg-treated parr (22%) than in the control (2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castrated precocious males and immature parr. In Experiment 3, castrated + T 50 μg, castrated + T 500 μg, and sham-operated fish showed upstream Migratory Behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated groups, respectively. In each experiment, plasma levels of T 4 in migrants were lower than those in nonmigrants, whereas plasma levels of T 3 did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon.
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The involvement of sex steroid hormones in downstream and upstream Migratory Behavior of masu salmon.
Comparative Biochemistry and Physiology B, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:From May through July when masu salmon, Oncorhynchus masou, commence downstream migration under natural conditions, yearling precocious male masu salmon (resident form) showed higher GSI and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in contrast to immature smolts (Migratory form). From March through September coinciding with the upstream migration period, 2-year-old male and female adults also showed higher GSI and plasma levels of T, estradiol-17β (E2) 11-KT, 17α-hydroxyprogesterone and 17α,20β-dihydroxy-4-pregnene-3-one (DHP). In order to test the effects of steroid hormones on Migratory Behaviors, silascone tube capsules containing 500 μg of T, E2, 11-KT, DHP, or a vehicle was implanted into smolts, castrated precocious males, or immature parr, and downstream and upstream Behavior were observed in artificial raceways in spring and autumn. Downstream Behavior of smolts was inhibited significantly by T, E2 and 11-KT. Upstream Behavior was stimulated by T and 11-KT in castrated precocious males and stimulated by T, E2 and 11-KT in immature parr. These results indicate that T, E2 and 11-KT are the factors regulating downstream and upstream Migratory Behavior. In particular, because of its changing patterns in plasma and significant effects, T, the common precursor hormone of E2 (female) and 11-KT (male), is considered to play central roles in both types of Behavior.
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Inhibitory effects of testosterone on downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
Zoological Science, 2000Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of testosterone (T) on downstream Migratory Behavior of yearling masu salmon, Oncorhynchus masou, were studied during its downstream Migratory period using artificial raceways. In experiment 1, 22 and 19 smolts were implanted with a medical silicone tube capsules containing 500μg of T or vehicle only. These groups were transferred together to the upper pond of artificial raceway which was connected to the lower pond through fish-way. Downstream Migratory Behavior was then observed for 1 week. In experiment 2, T500μg-, T50μg-, and T5μg-treated smolts, control smolts, and precociously mature males were transferred to the upper pond of the raceway and downstream Migratory Behavior was observed for 2 months. In experiment 3, 40 smolts were implanted with capsules containing 500μg of T or vehicle only. These groups were transferred separately to the upper ponds of raceways and downstream Migratory Behavior was observed for 3 weeks. In each experiment, injection of T caused increases in pla...
Jean-marie Zahm - One of the best experts on this subject based on the ideXlab platform.
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Epigallocatechin-3-gallate (EGCG) inhibits the Migratory Behavior of tumor bronchial epithelial cells
Respiratory research, 2008Co-Authors: S. Hazgui, Arnaud Bonnomet, Béatrice Nawrocki-raby, Magali Milliot, Christine Terryn, Jérôme Cutrona, Myriam Polette, Philippe Birembaut, Jean-marie ZahmAbstract:Background Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell Migratory Behavior.
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epigallocatechin 3 gallate egcg inhibits the Migratory Behavior of tumor bronchial epithelial cells
Respiratory Research, 2008Co-Authors: S. Hazgui, Arnaud Bonnomet, Magali Milliot, Christine Terryn, Jérôme Cutrona, Myriam Polette, Philippe Birembaut, Beatrice Nawrockiraby, Jean-marie ZahmAbstract:Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell Migratory Behavior. The effect of EGCG (at concentrations lower than 10 μg/ml) on the migration speed of invasive cells was assessed by using 2D and 3D models of cell culture. We also studied the effects of EGCG on proteinases expression by RT-PCR analysis. By immunocytochemistry, we analyzed alterations of vimentin organization in presence of different concentrations of EGCG. We observed that EGCG had an inhibitory effect of cell migration in 2D and 3D cell culture models. EGCG also inhibited MMP-2 mRNA and protein expression and altered the intermediate filaments of vimentin. Taken together, our results demonstrate that EGCG is able to inhibit the migration of bronchial tumor cells and could therefore be an attractive candidate to treat tumor invasion and cell migration.
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Epigallocatechin-3-gallate (EGCG) inhibits the Migratory Behavior of tumor bronchial epithelial cells.
Microbial Pathogenesis, 2008Co-Authors: S. Hazgui, Arnaud Bonnomet, Béatrice Nawrocki-raby, Magali Milliot, Christine Terryn, Jérôme Cutrona, Myriam Polette, Philippe Birembaut, Jean-marie ZahmAbstract:BACKGROUND: Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell Migratory Behavior. METHODS: The effect of EGCG (at concentrations lower than 10 microg/ml) on the migration speed of invasive cells was assessed by using 2D and 3D models of cell culture. We also studied the effects of EGCG on proteinases expression by RT-PCR analysis. By immunocytochemistry, we analyzed alterations of vimentin organization in presence of different concentrations of EGCG. RESULTS: We observed that EGCG had an inhibitory effect of cell migration in 2D and 3D cell culture models. EGCG also inhibited MMP-2 mRNA and protein expression and altered the intermediate filaments of vimentin. CONCLUSION: Taken together, our results demonstrate that EGCG is able to inhibit the migration of bronchial tumor cells and could therefore be an attractive candidate to treat tumor invasion and cell migration.
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3D culture model and computer-assisted videomicroscopy to analyze Migratory Behavior of noninvasive and invasive bronchial epithelial cells.
American Journal of Physiology - Cell Physiology, 2005Co-Authors: S. Hazgui, Béatrice Nawrocki-raby, Jérôme Cutrona, Myriam Polette, Philippe Birembaut, Noël Bonnet, Lotfi Chouchane, Jean-marie ZahmAbstract:To date, most of the studies in the field of cell migration have been applied to two-dimensional (2D) models. To mimic the three-dimensional (3D) conditions similar to those observed in vivo during tumor invasion, we developed a 3D model of cell migration in which cells were embedded in a collagen I matrix placed in a double-compartment chamber. Using time-lapse videomicroscopy and interactive cell tracking in a four-dimensional data set, we determined the cell trajectories and their migration kinetics. We compared the 2D and 3D Migratory Behavior of a noninvasive cell line (16HBE) with the Migratory Behavior of an invasive cell line (BZR). Our results show that the 3D migration kinetics of the noninvasive cell line were lower than the migration kinetics of the invasive cell line. In contrast, in 2D models, no significant difference was observed between the two cell lines. To validate our 3D model, we further investigated the effect of epidermal growth factor (EGF), a promoter of tumor cell motility and invasion on the noninvasive cell line (16HBE). EGF increased significantly the migration kinetics of the noninvasive cell line. Our results show that the 3D model of cell migration allowed us to differentiate the Migratory Behavior of invasive and noninvasive cells and that such a model can help in the development of molecular targeted therapy as it approaches the in vivo conditions.
Arimune Munakata - One of the best experts on this subject based on the ideXlab platform.
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Effects of growth hormone and cortisol on the downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
General and comparative endocrinology, 2006Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of ovine growth hormone (oGH) and cortisol on downstream Migratory Behavior in yearling (1 + ) smolts and underyearling (0 + ) parr of masu salmon, Oncorhynchus masou , were examined during the downstream Migratory period in spring using artificial raceways. In May, each of 22 1 + smolts and 0 + parr were implanted with cholesterol pellets containing 250 μg of oGH and/or 2 mg of cortisol. Their downstream Migratory Behavior was subsequently observed in artificial raceways, along with control groups 4–23 days after implantation. In 1 + smolts, the frequency of downstream Migratory Behavior was 23%, 18%, 72%, and 82% in the control, oGH, cortisol, and oGH + cortisol-treated groups, respectively. The frequency was significantly higher in the cortisol and oGH + cortisol-treated groups than in the control and oGH-treated groups. In 0 + parr, the frequency of downstream Migratory Behavior in the cortisol (82%) and cortisol + oGH-treated (90%) groups was significantly higher than in the control (18%) and oGH-treated (0%) groups. These results indicate that cortisol is an important endocrine factor inducing downstream Migratory Behavior in both 1 + smolt and 0 + parr of masu salmon.
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Effects of Low pH on Upstream Migratory Behavior in Land-Locked Sockeye Salmon Oncorhynchus nerka
Water Air and Soil Pollution, 2001Co-Authors: Kazumasa Ikuta, Arimune Munakata, Masafumi Amano, Katsumi Aida, Shoji KitamuraAbstract:The effects of low pH on upstream Migratory Behavior in land-locked sockeye salmon Oncorhynchus nerka were examined using 2-way flow-through channels. Homing mature salmon captured at the mouth of their native stream were used. When neutral (pH 6.7) hatchery water of the same origin as native stream water was allowed to flow through both channels, fish showed active swimming into both channels during a 48 hrs period. When water pH in one channel was lowered by the addition of sulfuric acid, salmon completely ceased upstream swimming Behavior into areas of pH lower than 6.0, and swam up into only neutral areas. In the lower pond of the 2-way channels, fish also avoided acidic areas even when average pH was 6.2. Since it has been reported that extremely slight changes in pH such as in the pH 6 range inhibits spawning Behavior in this species, it is suggested that land-locked sockeye salmon have a sensitive ability to perceive even slight acidity, and avoid environments which may be deleterious to their offspring.
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the effects of testosterone on upstream Migratory Behavior in masu salmon oncorhynchus masou
General and Comparative Endocrinology, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract Effects of testosterone (T) on upstream Migratory Behavior in masu salmon, Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 μg of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream Migratory Behavior of yearling immature parr implanted with a capsule containing T 500 μg or vehicle was observed from September through November. In Experiment 3, upstream Migratory Behavior of castrated, castrated + T 50 μg, castrated + T 500 μg, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream Migratory Behavior of the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T 4 ), and triiodothyronine (T 3 ) by radioimmunoassay. Administration of T caused increases in plasma T levels within the physiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 μg, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 μg and sham-operated groups than in the castrated group. In Experiment 2, the frequency was higher in T 500 μg-treated parr (22%) than in the control (2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castrated precocious males and immature parr. In Experiment 3, castrated + T 50 μg, castrated + T 500 μg, and sham-operated fish showed upstream Migratory Behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated groups, respectively. In each experiment, plasma levels of T 4 in migrants were lower than those in nonmigrants, whereas plasma levels of T 3 did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon.
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The involvement of sex steroid hormones in downstream and upstream Migratory Behavior of masu salmon.
Comparative Biochemistry and Physiology B, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:From May through July when masu salmon, Oncorhynchus masou, commence downstream migration under natural conditions, yearling precocious male masu salmon (resident form) showed higher GSI and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in contrast to immature smolts (Migratory form). From March through September coinciding with the upstream migration period, 2-year-old male and female adults also showed higher GSI and plasma levels of T, estradiol-17β (E2) 11-KT, 17α-hydroxyprogesterone and 17α,20β-dihydroxy-4-pregnene-3-one (DHP). In order to test the effects of steroid hormones on Migratory Behaviors, silascone tube capsules containing 500 μg of T, E2, 11-KT, DHP, or a vehicle was implanted into smolts, castrated precocious males, or immature parr, and downstream and upstream Behavior were observed in artificial raceways in spring and autumn. Downstream Behavior of smolts was inhibited significantly by T, E2 and 11-KT. Upstream Behavior was stimulated by T and 11-KT in castrated precocious males and stimulated by T, E2 and 11-KT in immature parr. These results indicate that T, E2 and 11-KT are the factors regulating downstream and upstream Migratory Behavior. In particular, because of its changing patterns in plasma and significant effects, T, the common precursor hormone of E2 (female) and 11-KT (male), is considered to play central roles in both types of Behavior.
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Inhibitory effects of testosterone on downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
Zoological Science, 2000Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of testosterone (T) on downstream Migratory Behavior of yearling masu salmon, Oncorhynchus masou, were studied during its downstream Migratory period using artificial raceways. In experiment 1, 22 and 19 smolts were implanted with a medical silicone tube capsules containing 500μg of T or vehicle only. These groups were transferred together to the upper pond of artificial raceway which was connected to the lower pond through fish-way. Downstream Migratory Behavior was then observed for 1 week. In experiment 2, T500μg-, T50μg-, and T5μg-treated smolts, control smolts, and precociously mature males were transferred to the upper pond of the raceway and downstream Migratory Behavior was observed for 2 months. In experiment 3, 40 smolts were implanted with capsules containing 500μg of T or vehicle only. These groups were transferred separately to the upper ponds of raceways and downstream Migratory Behavior was observed for 3 weeks. In each experiment, injection of T caused increases in pla...
Shoji Kitamura - One of the best experts on this subject based on the ideXlab platform.
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Effects of growth hormone and cortisol on the downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
General and comparative endocrinology, 2006Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of ovine growth hormone (oGH) and cortisol on downstream Migratory Behavior in yearling (1 + ) smolts and underyearling (0 + ) parr of masu salmon, Oncorhynchus masou , were examined during the downstream Migratory period in spring using artificial raceways. In May, each of 22 1 + smolts and 0 + parr were implanted with cholesterol pellets containing 250 μg of oGH and/or 2 mg of cortisol. Their downstream Migratory Behavior was subsequently observed in artificial raceways, along with control groups 4–23 days after implantation. In 1 + smolts, the frequency of downstream Migratory Behavior was 23%, 18%, 72%, and 82% in the control, oGH, cortisol, and oGH + cortisol-treated groups, respectively. The frequency was significantly higher in the cortisol and oGH + cortisol-treated groups than in the control and oGH-treated groups. In 0 + parr, the frequency of downstream Migratory Behavior in the cortisol (82%) and cortisol + oGH-treated (90%) groups was significantly higher than in the control (18%) and oGH-treated (0%) groups. These results indicate that cortisol is an important endocrine factor inducing downstream Migratory Behavior in both 1 + smolt and 0 + parr of masu salmon.
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Effects of Low pH on Upstream Migratory Behavior in Land-Locked Sockeye Salmon Oncorhynchus nerka
Water Air and Soil Pollution, 2001Co-Authors: Kazumasa Ikuta, Arimune Munakata, Masafumi Amano, Katsumi Aida, Shoji KitamuraAbstract:The effects of low pH on upstream Migratory Behavior in land-locked sockeye salmon Oncorhynchus nerka were examined using 2-way flow-through channels. Homing mature salmon captured at the mouth of their native stream were used. When neutral (pH 6.7) hatchery water of the same origin as native stream water was allowed to flow through both channels, fish showed active swimming into both channels during a 48 hrs period. When water pH in one channel was lowered by the addition of sulfuric acid, salmon completely ceased upstream swimming Behavior into areas of pH lower than 6.0, and swam up into only neutral areas. In the lower pond of the 2-way channels, fish also avoided acidic areas even when average pH was 6.2. Since it has been reported that extremely slight changes in pH such as in the pH 6 range inhibits spawning Behavior in this species, it is suggested that land-locked sockeye salmon have a sensitive ability to perceive even slight acidity, and avoid environments which may be deleterious to their offspring.
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the effects of testosterone on upstream Migratory Behavior in masu salmon oncorhynchus masou
General and Comparative Endocrinology, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract Effects of testosterone (T) on upstream Migratory Behavior in masu salmon, Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 μg of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream Migratory Behavior of yearling immature parr implanted with a capsule containing T 500 μg or vehicle was observed from September through November. In Experiment 3, upstream Migratory Behavior of castrated, castrated + T 50 μg, castrated + T 500 μg, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream Migratory Behavior of the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T 4 ), and triiodothyronine (T 3 ) by radioimmunoassay. Administration of T caused increases in plasma T levels within the physiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 μg, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 μg and sham-operated groups than in the castrated group. In Experiment 2, the frequency was higher in T 500 μg-treated parr (22%) than in the control (2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castrated precocious males and immature parr. In Experiment 3, castrated + T 50 μg, castrated + T 500 μg, and sham-operated fish showed upstream Migratory Behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated groups, respectively. In each experiment, plasma levels of T 4 in migrants were lower than those in nonmigrants, whereas plasma levels of T 3 did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon.
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The involvement of sex steroid hormones in downstream and upstream Migratory Behavior of masu salmon.
Comparative Biochemistry and Physiology B, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:From May through July when masu salmon, Oncorhynchus masou, commence downstream migration under natural conditions, yearling precocious male masu salmon (resident form) showed higher GSI and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in contrast to immature smolts (Migratory form). From March through September coinciding with the upstream migration period, 2-year-old male and female adults also showed higher GSI and plasma levels of T, estradiol-17β (E2) 11-KT, 17α-hydroxyprogesterone and 17α,20β-dihydroxy-4-pregnene-3-one (DHP). In order to test the effects of steroid hormones on Migratory Behaviors, silascone tube capsules containing 500 μg of T, E2, 11-KT, DHP, or a vehicle was implanted into smolts, castrated precocious males, or immature parr, and downstream and upstream Behavior were observed in artificial raceways in spring and autumn. Downstream Behavior of smolts was inhibited significantly by T, E2 and 11-KT. Upstream Behavior was stimulated by T and 11-KT in castrated precocious males and stimulated by T, E2 and 11-KT in immature parr. These results indicate that T, E2 and 11-KT are the factors regulating downstream and upstream Migratory Behavior. In particular, because of its changing patterns in plasma and significant effects, T, the common precursor hormone of E2 (female) and 11-KT (male), is considered to play central roles in both types of Behavior.
-
Inhibitory effects of testosterone on downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
Zoological Science, 2000Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of testosterone (T) on downstream Migratory Behavior of yearling masu salmon, Oncorhynchus masou, were studied during its downstream Migratory period using artificial raceways. In experiment 1, 22 and 19 smolts were implanted with a medical silicone tube capsules containing 500μg of T or vehicle only. These groups were transferred together to the upper pond of artificial raceway which was connected to the lower pond through fish-way. Downstream Migratory Behavior was then observed for 1 week. In experiment 2, T500μg-, T50μg-, and T5μg-treated smolts, control smolts, and precociously mature males were transferred to the upper pond of the raceway and downstream Migratory Behavior was observed for 2 months. In experiment 3, 40 smolts were implanted with capsules containing 500μg of T or vehicle only. These groups were transferred separately to the upper ponds of raceways and downstream Migratory Behavior was observed for 3 weeks. In each experiment, injection of T caused increases in pla...
Kazumasa Ikuta - One of the best experts on this subject based on the ideXlab platform.
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Effects of growth hormone and cortisol on the downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
General and comparative endocrinology, 2006Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of ovine growth hormone (oGH) and cortisol on downstream Migratory Behavior in yearling (1 + ) smolts and underyearling (0 + ) parr of masu salmon, Oncorhynchus masou , were examined during the downstream Migratory period in spring using artificial raceways. In May, each of 22 1 + smolts and 0 + parr were implanted with cholesterol pellets containing 250 μg of oGH and/or 2 mg of cortisol. Their downstream Migratory Behavior was subsequently observed in artificial raceways, along with control groups 4–23 days after implantation. In 1 + smolts, the frequency of downstream Migratory Behavior was 23%, 18%, 72%, and 82% in the control, oGH, cortisol, and oGH + cortisol-treated groups, respectively. The frequency was significantly higher in the cortisol and oGH + cortisol-treated groups than in the control and oGH-treated groups. In 0 + parr, the frequency of downstream Migratory Behavior in the cortisol (82%) and cortisol + oGH-treated (90%) groups was significantly higher than in the control (18%) and oGH-treated (0%) groups. These results indicate that cortisol is an important endocrine factor inducing downstream Migratory Behavior in both 1 + smolt and 0 + parr of masu salmon.
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Effects of Low pH on Upstream Migratory Behavior in Land-Locked Sockeye Salmon Oncorhynchus nerka
Water Air and Soil Pollution, 2001Co-Authors: Kazumasa Ikuta, Arimune Munakata, Masafumi Amano, Katsumi Aida, Shoji KitamuraAbstract:The effects of low pH on upstream Migratory Behavior in land-locked sockeye salmon Oncorhynchus nerka were examined using 2-way flow-through channels. Homing mature salmon captured at the mouth of their native stream were used. When neutral (pH 6.7) hatchery water of the same origin as native stream water was allowed to flow through both channels, fish showed active swimming into both channels during a 48 hrs period. When water pH in one channel was lowered by the addition of sulfuric acid, salmon completely ceased upstream swimming Behavior into areas of pH lower than 6.0, and swam up into only neutral areas. In the lower pond of the 2-way channels, fish also avoided acidic areas even when average pH was 6.2. Since it has been reported that extremely slight changes in pH such as in the pH 6 range inhibits spawning Behavior in this species, it is suggested that land-locked sockeye salmon have a sensitive ability to perceive even slight acidity, and avoid environments which may be deleterious to their offspring.
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the effects of testosterone on upstream Migratory Behavior in masu salmon oncorhynchus masou
General and Comparative Endocrinology, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract Effects of testosterone (T) on upstream Migratory Behavior in masu salmon, Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 μg of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream Migratory Behavior of yearling immature parr implanted with a capsule containing T 500 μg or vehicle was observed from September through November. In Experiment 3, upstream Migratory Behavior of castrated, castrated + T 50 μg, castrated + T 500 μg, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream Migratory Behavior of the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T 4 ), and triiodothyronine (T 3 ) by radioimmunoassay. Administration of T caused increases in plasma T levels within the physiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 μg, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 μg and sham-operated groups than in the castrated group. In Experiment 2, the frequency was higher in T 500 μg-treated parr (22%) than in the control (2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castrated precocious males and immature parr. In Experiment 3, castrated + T 50 μg, castrated + T 500 μg, and sham-operated fish showed upstream Migratory Behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 μg-, T 500 μg-, and T 1000 μg-treated groups, respectively. In each experiment, plasma levels of T 4 in migrants were lower than those in nonmigrants, whereas plasma levels of T 3 did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon.
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The involvement of sex steroid hormones in downstream and upstream Migratory Behavior of masu salmon.
Comparative Biochemistry and Physiology B, 2001Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:From May through July when masu salmon, Oncorhynchus masou, commence downstream migration under natural conditions, yearling precocious male masu salmon (resident form) showed higher GSI and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in contrast to immature smolts (Migratory form). From March through September coinciding with the upstream migration period, 2-year-old male and female adults also showed higher GSI and plasma levels of T, estradiol-17β (E2) 11-KT, 17α-hydroxyprogesterone and 17α,20β-dihydroxy-4-pregnene-3-one (DHP). In order to test the effects of steroid hormones on Migratory Behaviors, silascone tube capsules containing 500 μg of T, E2, 11-KT, DHP, or a vehicle was implanted into smolts, castrated precocious males, or immature parr, and downstream and upstream Behavior were observed in artificial raceways in spring and autumn. Downstream Behavior of smolts was inhibited significantly by T, E2 and 11-KT. Upstream Behavior was stimulated by T and 11-KT in castrated precocious males and stimulated by T, E2 and 11-KT in immature parr. These results indicate that T, E2 and 11-KT are the factors regulating downstream and upstream Migratory Behavior. In particular, because of its changing patterns in plasma and significant effects, T, the common precursor hormone of E2 (female) and 11-KT (male), is considered to play central roles in both types of Behavior.
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Inhibitory effects of testosterone on downstream Migratory Behavior in masu salmon, Oncorhynchus masou.
Zoological Science, 2000Co-Authors: Arimune Munakata, Masafumi Amano, Kazumasa Ikuta, Shoji Kitamura, Katsumi AidaAbstract:Abstract The effects of testosterone (T) on downstream Migratory Behavior of yearling masu salmon, Oncorhynchus masou, were studied during its downstream Migratory period using artificial raceways. In experiment 1, 22 and 19 smolts were implanted with a medical silicone tube capsules containing 500μg of T or vehicle only. These groups were transferred together to the upper pond of artificial raceway which was connected to the lower pond through fish-way. Downstream Migratory Behavior was then observed for 1 week. In experiment 2, T500μg-, T50μg-, and T5μg-treated smolts, control smolts, and precociously mature males were transferred to the upper pond of the raceway and downstream Migratory Behavior was observed for 2 months. In experiment 3, 40 smolts were implanted with capsules containing 500μg of T or vehicle only. These groups were transferred separately to the upper ponds of raceways and downstream Migratory Behavior was observed for 3 weeks. In each experiment, injection of T caused increases in pla...