The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Cleida A Oliveira - One of the best experts on this subject based on the ideXlab platform.
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Roosters affected by epididymal lithiasis present local alteration in vitamin d3 testosterone and estradiol levels as well as estrogen receptor 2 beta expression
Reproduction, 2011Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Rex A Hess, Lilian C Praes, Cleida A OliveiraAbstract:Epididymal lithiasis is a reproductive dysfunction of Roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of Roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected Roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of Roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.
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Occurrence and cellular distribution of estrogen receptors ERα and ERβ in the testis and epididymal region of Roosters
General and Comparative Endocrinology, 2010Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Cleida A OliveiraAbstract:Abstract Estrogen signaling is required for the maintenance of male reproductive function and is mediated by the estrogen receptors ERα and ERβ. These receptors are widely distributed in mammalian reproductive tissues, but information is limited in non-mammalian species including birds. The aim of this study was to investigate the occurrence and cellular distribution of ERα and ERβ in the testis and epididymal region of Roosters. The results showed for the first time that ERβ was the predominant receptor detected in the testis, being expressed in the somatic and some germ cells. Within the epididymal region, ERβ was strongly expressed in all segments, whereas the most intense reaction for ERα was found in the distal efferent ductules. The differential expression of ERα and ERβ within the rooster testis and epididymal region suggests that these organs may be a target for different actions of estrogen.
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distribution of vitamin d3 receptor in the epididymal region of Roosters gallus domesticus is cell and segment specific
General and Comparative Endocrinology, 2007Co-Authors: Rubem A P Dornas, German A B Mahecha, Andre G Oliveira, Evanguedes Kalapothakis, Rex A Hess, Cleida A OliveiraAbstract:Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3 in the avian reproductive tract remain unknown. The aim of the present study was to investigate the expression and cellular distribution of VDR in the epididymal region of Roosters. VDR expression was investigated by Western blotting analysis and the tissue distribution of the receptor was determined by immunohistochemistry. The Western blotting assay revealed a major VDR protein band of 61 kDa in the epididymal region of rooster. Nuclear VDR expression was found in all segments of the epididymal region, namely rete testis, eVerent ductules, connecting ducts and epididymal ducts. Nonciliated cells of the distal eVerent ductules showed the highest levels of VDR expression, followed by the proximal eVerent ductules and rete testis. The connecting and epididymal ducts showed less intense VDR immunostaining. The diVerential VDR expression in the epididymal region segments reveals that several extratesticular ducts may be target for vitamin D3 action and suggests that vitamin D3 may have a regional-speciWc function, such as calcium transport, that is modulated through VDR activity.
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epididymal lithiasis in Roosters and efferent ductule and testicular damage
Reproduction, 2002Co-Authors: German A B Mahecha, Cleida A Oliveira, K Balzuweit, Rex A HessAbstract:Epididymal stones have been reported in Roosters in the USA and Japan. The cause of this dysfunction, which is associated with low fertility, is not known. The hypothesis of the present study is that a potential cause is the aggressive selection of birds over many centuries based upon female egg laying traits, without concern for potential effects on the male. If this hypothesis is correct, one potential consequence would be the presence of epididymal stones only in domesticated fowl and this observation would be worldwide in distribution. The present study investigated epididymal lithiasis in Brazilian crossbreed Roosters and two other fowl strains, in addition to several domestic and wild bird species. The efferent ductules contained stones in 94.3% of the Roosters, but stones were absent in all other domestic and wild birds. The stones were irregular in shape, size and colour and consisted mainly of calcium. In affected Roosters, the efferent ductules showed epithelial cell vacuolization and sloughing and peritubular mononuclear cell infiltration, culminating with atrophy. Signs of epithelial re-canalization were seen in ductules occluded by abnormal content, such as stones. In the testis, decrease in mass, sloughing of epithelium, mononuclear cell infiltration and tubular atrophy occurred. No correlation was found between the occurrence of stones and a positive test for ELISA IBV (infectious bronchitis virus), or between the number of stones and calcium concentration in water and food, indicating that IBV infection and calcium in the diet were not related to stones formation. This study confirms and extends information about the epididymal lithiasis, which appears to be unique for Roosters but to occur around the world. The severity of the lesion points to potentially severe economical impact in the poultry industry.
German A B Mahecha - One of the best experts on this subject based on the ideXlab platform.
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Roosters affected by epididymal lithiasis present local alteration in vitamin d3 testosterone and estradiol levels as well as estrogen receptor 2 beta expression
Reproduction, 2011Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Rex A Hess, Lilian C Praes, Cleida A OliveiraAbstract:Epididymal lithiasis is a reproductive dysfunction of Roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of Roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected Roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of Roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.
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Occurrence and cellular distribution of estrogen receptors ERα and ERβ in the testis and epididymal region of Roosters
General and Comparative Endocrinology, 2010Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Cleida A OliveiraAbstract:Abstract Estrogen signaling is required for the maintenance of male reproductive function and is mediated by the estrogen receptors ERα and ERβ. These receptors are widely distributed in mammalian reproductive tissues, but information is limited in non-mammalian species including birds. The aim of this study was to investigate the occurrence and cellular distribution of ERα and ERβ in the testis and epididymal region of Roosters. The results showed for the first time that ERβ was the predominant receptor detected in the testis, being expressed in the somatic and some germ cells. Within the epididymal region, ERβ was strongly expressed in all segments, whereas the most intense reaction for ERα was found in the distal efferent ductules. The differential expression of ERα and ERβ within the rooster testis and epididymal region suggests that these organs may be a target for different actions of estrogen.
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distribution of vitamin d3 receptor in the epididymal region of Roosters gallus domesticus is cell and segment specific
General and Comparative Endocrinology, 2007Co-Authors: Rubem A P Dornas, German A B Mahecha, Andre G Oliveira, Evanguedes Kalapothakis, Rex A Hess, Cleida A OliveiraAbstract:Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3 in the avian reproductive tract remain unknown. The aim of the present study was to investigate the expression and cellular distribution of VDR in the epididymal region of Roosters. VDR expression was investigated by Western blotting analysis and the tissue distribution of the receptor was determined by immunohistochemistry. The Western blotting assay revealed a major VDR protein band of 61 kDa in the epididymal region of rooster. Nuclear VDR expression was found in all segments of the epididymal region, namely rete testis, eVerent ductules, connecting ducts and epididymal ducts. Nonciliated cells of the distal eVerent ductules showed the highest levels of VDR expression, followed by the proximal eVerent ductules and rete testis. The connecting and epididymal ducts showed less intense VDR immunostaining. The diVerential VDR expression in the epididymal region segments reveals that several extratesticular ducts may be target for vitamin D3 action and suggests that vitamin D3 may have a regional-speciWc function, such as calcium transport, that is modulated through VDR activity.
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epididymal lithiasis in Roosters and efferent ductule and testicular damage
Reproduction, 2002Co-Authors: German A B Mahecha, Cleida A Oliveira, K Balzuweit, Rex A HessAbstract:Epididymal stones have been reported in Roosters in the USA and Japan. The cause of this dysfunction, which is associated with low fertility, is not known. The hypothesis of the present study is that a potential cause is the aggressive selection of birds over many centuries based upon female egg laying traits, without concern for potential effects on the male. If this hypothesis is correct, one potential consequence would be the presence of epididymal stones only in domesticated fowl and this observation would be worldwide in distribution. The present study investigated epididymal lithiasis in Brazilian crossbreed Roosters and two other fowl strains, in addition to several domestic and wild bird species. The efferent ductules contained stones in 94.3% of the Roosters, but stones were absent in all other domestic and wild birds. The stones were irregular in shape, size and colour and consisted mainly of calcium. In affected Roosters, the efferent ductules showed epithelial cell vacuolization and sloughing and peritubular mononuclear cell infiltration, culminating with atrophy. Signs of epithelial re-canalization were seen in ductules occluded by abnormal content, such as stones. In the testis, decrease in mass, sloughing of epithelium, mononuclear cell infiltration and tubular atrophy occurred. No correlation was found between the occurrence of stones and a positive test for ELISA IBV (infectious bronchitis virus), or between the number of stones and calcium concentration in water and food, indicating that IBV infection and calcium in the diet were not related to stones formation. This study confirms and extends information about the epididymal lithiasis, which appears to be unique for Roosters but to occur around the world. The severity of the lesion points to potentially severe economical impact in the poultry industry.
Andre G Oliveira - One of the best experts on this subject based on the ideXlab platform.
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Roosters affected by epididymal lithiasis present local alteration in vitamin d3 testosterone and estradiol levels as well as estrogen receptor 2 beta expression
Reproduction, 2011Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Rex A Hess, Lilian C Praes, Cleida A OliveiraAbstract:Epididymal lithiasis is a reproductive dysfunction of Roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of Roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected Roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of Roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.
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Occurrence and cellular distribution of estrogen receptors ERα and ERβ in the testis and epididymal region of Roosters
General and Comparative Endocrinology, 2010Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Cleida A OliveiraAbstract:Abstract Estrogen signaling is required for the maintenance of male reproductive function and is mediated by the estrogen receptors ERα and ERβ. These receptors are widely distributed in mammalian reproductive tissues, but information is limited in non-mammalian species including birds. The aim of this study was to investigate the occurrence and cellular distribution of ERα and ERβ in the testis and epididymal region of Roosters. The results showed for the first time that ERβ was the predominant receptor detected in the testis, being expressed in the somatic and some germ cells. Within the epididymal region, ERβ was strongly expressed in all segments, whereas the most intense reaction for ERα was found in the distal efferent ductules. The differential expression of ERα and ERβ within the rooster testis and epididymal region suggests that these organs may be a target for different actions of estrogen.
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distribution of vitamin d3 receptor in the epididymal region of Roosters gallus domesticus is cell and segment specific
General and Comparative Endocrinology, 2007Co-Authors: Rubem A P Dornas, German A B Mahecha, Andre G Oliveira, Evanguedes Kalapothakis, Rex A Hess, Cleida A OliveiraAbstract:Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3 in the avian reproductive tract remain unknown. The aim of the present study was to investigate the expression and cellular distribution of VDR in the epididymal region of Roosters. VDR expression was investigated by Western blotting analysis and the tissue distribution of the receptor was determined by immunohistochemistry. The Western blotting assay revealed a major VDR protein band of 61 kDa in the epididymal region of rooster. Nuclear VDR expression was found in all segments of the epididymal region, namely rete testis, eVerent ductules, connecting ducts and epididymal ducts. Nonciliated cells of the distal eVerent ductules showed the highest levels of VDR expression, followed by the proximal eVerent ductules and rete testis. The connecting and epididymal ducts showed less intense VDR immunostaining. The diVerential VDR expression in the epididymal region segments reveals that several extratesticular ducts may be target for vitamin D3 action and suggests that vitamin D3 may have a regional-speciWc function, such as calcium transport, that is modulated through VDR activity.
Rubem A P Dornas - One of the best experts on this subject based on the ideXlab platform.
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Roosters affected by epididymal lithiasis present local alteration in vitamin d3 testosterone and estradiol levels as well as estrogen receptor 2 beta expression
Reproduction, 2011Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Rex A Hess, Lilian C Praes, Cleida A OliveiraAbstract:Epididymal lithiasis is a reproductive dysfunction of Roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of Roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected Roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of Roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.
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Occurrence and cellular distribution of estrogen receptors ERα and ERβ in the testis and epididymal region of Roosters
General and Comparative Endocrinology, 2010Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Cleida A OliveiraAbstract:Abstract Estrogen signaling is required for the maintenance of male reproductive function and is mediated by the estrogen receptors ERα and ERβ. These receptors are widely distributed in mammalian reproductive tissues, but information is limited in non-mammalian species including birds. The aim of this study was to investigate the occurrence and cellular distribution of ERα and ERβ in the testis and epididymal region of Roosters. The results showed for the first time that ERβ was the predominant receptor detected in the testis, being expressed in the somatic and some germ cells. Within the epididymal region, ERβ was strongly expressed in all segments, whereas the most intense reaction for ERα was found in the distal efferent ductules. The differential expression of ERα and ERβ within the rooster testis and epididymal region suggests that these organs may be a target for different actions of estrogen.
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distribution of vitamin d3 receptor in the epididymal region of Roosters gallus domesticus is cell and segment specific
General and Comparative Endocrinology, 2007Co-Authors: Rubem A P Dornas, German A B Mahecha, Andre G Oliveira, Evanguedes Kalapothakis, Rex A Hess, Cleida A OliveiraAbstract:Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3 in the avian reproductive tract remain unknown. The aim of the present study was to investigate the expression and cellular distribution of VDR in the epididymal region of Roosters. VDR expression was investigated by Western blotting analysis and the tissue distribution of the receptor was determined by immunohistochemistry. The Western blotting assay revealed a major VDR protein band of 61 kDa in the epididymal region of rooster. Nuclear VDR expression was found in all segments of the epididymal region, namely rete testis, eVerent ductules, connecting ducts and epididymal ducts. Nonciliated cells of the distal eVerent ductules showed the highest levels of VDR expression, followed by the proximal eVerent ductules and rete testis. The connecting and epididymal ducts showed less intense VDR immunostaining. The diVerential VDR expression in the epididymal region segments reveals that several extratesticular ducts may be target for vitamin D3 action and suggests that vitamin D3 may have a regional-speciWc function, such as calcium transport, that is modulated through VDR activity.
Rex A Hess - One of the best experts on this subject based on the ideXlab platform.
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Roosters affected by epididymal lithiasis present local alteration in vitamin d3 testosterone and estradiol levels as well as estrogen receptor 2 beta expression
Reproduction, 2011Co-Authors: Andre G Oliveira, Rubem A P Dornas, German A B Mahecha, Rex A Hess, Lilian C Praes, Cleida A OliveiraAbstract:Epididymal lithiasis is a reproductive dysfunction of Roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of Roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected Roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of Roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.
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distribution of vitamin d3 receptor in the epididymal region of Roosters gallus domesticus is cell and segment specific
General and Comparative Endocrinology, 2007Co-Authors: Rubem A P Dornas, German A B Mahecha, Andre G Oliveira, Evanguedes Kalapothakis, Rex A Hess, Cleida A OliveiraAbstract:Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3 in the avian reproductive tract remain unknown. The aim of the present study was to investigate the expression and cellular distribution of VDR in the epididymal region of Roosters. VDR expression was investigated by Western blotting analysis and the tissue distribution of the receptor was determined by immunohistochemistry. The Western blotting assay revealed a major VDR protein band of 61 kDa in the epididymal region of rooster. Nuclear VDR expression was found in all segments of the epididymal region, namely rete testis, eVerent ductules, connecting ducts and epididymal ducts. Nonciliated cells of the distal eVerent ductules showed the highest levels of VDR expression, followed by the proximal eVerent ductules and rete testis. The connecting and epididymal ducts showed less intense VDR immunostaining. The diVerential VDR expression in the epididymal region segments reveals that several extratesticular ducts may be target for vitamin D3 action and suggests that vitamin D3 may have a regional-speciWc function, such as calcium transport, that is modulated through VDR activity.
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epididymal lithiasis in Roosters and efferent ductule and testicular damage
Reproduction, 2002Co-Authors: German A B Mahecha, Cleida A Oliveira, K Balzuweit, Rex A HessAbstract:Epididymal stones have been reported in Roosters in the USA and Japan. The cause of this dysfunction, which is associated with low fertility, is not known. The hypothesis of the present study is that a potential cause is the aggressive selection of birds over many centuries based upon female egg laying traits, without concern for potential effects on the male. If this hypothesis is correct, one potential consequence would be the presence of epididymal stones only in domesticated fowl and this observation would be worldwide in distribution. The present study investigated epididymal lithiasis in Brazilian crossbreed Roosters and two other fowl strains, in addition to several domestic and wild bird species. The efferent ductules contained stones in 94.3% of the Roosters, but stones were absent in all other domestic and wild birds. The stones were irregular in shape, size and colour and consisted mainly of calcium. In affected Roosters, the efferent ductules showed epithelial cell vacuolization and sloughing and peritubular mononuclear cell infiltration, culminating with atrophy. Signs of epithelial re-canalization were seen in ductules occluded by abnormal content, such as stones. In the testis, decrease in mass, sloughing of epithelium, mononuclear cell infiltration and tubular atrophy occurred. No correlation was found between the occurrence of stones and a positive test for ELISA IBV (infectious bronchitis virus), or between the number of stones and calcium concentration in water and food, indicating that IBV infection and calcium in the diet were not related to stones formation. This study confirms and extends information about the epididymal lithiasis, which appears to be unique for Roosters but to occur around the world. The severity of the lesion points to potentially severe economical impact in the poultry industry.
