The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Mitsuo Iida - One of the best experts on this subject based on the ideXlab platform.
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Chronic central infusion of orexin-A increases arterial pressure in rats.
Brain research bulletin, 2002Co-Authors: Yingzi Lin, Kiyoshi Matsumura, Takuya Tsuchihashi, Isao Abe, Mitsuo IidaAbstract:Abstract We determined the cardiovascular responses as well as food and water intakes to chronic intracerebroventricular administration of orexin-A and orexin-B for 14 days in conscious rats. Chronic intracerebroventricular infusion of orexin-A (50 pmol/h) elicited a significant increase in systolic blood pressure on the third day (+15.6 ± 2.9 mm Hg), and during the continuous intracerebroventricular infusion of orexin-A the blood pressure returned to the baseline levels at day 14. In contrast, chronic intracerebroventricular infusion of orexin-B (50 pmol/h) failed to change systolic blood pressure during the 14 days of experimental periods. Chronic intracerebroventricular infusions of neither orexin-A nor orexin-B changed urinary catecholamine excretions, food and water intakes, and urine volumes at 7 and 14 days of infusion periods. Mean arterial pressure directly measured at 14 days did not differ among the groups of orexin-A, orexin-B, and artificial cerebrospinal fluid treatments. Both intravenous injections of pentolinium (5 mg/kg), a Ganglion Blocking Agent, and CV-11974 (0.05 mg/kg), an AT 1 receptor antagonist, decreased arterial pressure; however, these responses were not different among the groups. These results suggest that central orexin-A participates in the short-term regulation of blood pressure; however, the contributions of central orexins to the long-term regulations of blood pressure, sympathetic nervous system, and appetite may be little.
Pa Robbins - One of the best experts on this subject based on the ideXlab platform.
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Lack of involvement of the autonomic nervous system in early ventilatory and pulmonary vascular acclimatization to hypoxia in humans.
'Wiley', 2007Co-Authors: Liu C, Tg Smith, Gm Balanos, Brooks J, Crosby A, Herigstad M, Kl Dorrington, Pa RobbinsAbstract:The activity within the autonomic nervous system may be altered following sustained exposure to hypoxia, and it is possible that this increase in activity underlies the early acclimatization of both ventilation and the pulmonary vasculature to hypoxia. To test this hypothesis, seven individuals were infused with the Ganglionic blocker trimetaphan before and after an 8 h exposure to hypoxia. The short half-life of trimetaphan should ensure that the initial infusion does not affect acclimatization to the 8 h hypoxia exposure, and the use of a Ganglion Blocking Agent should inhibit activity within all branches of the autonomic nervous system. During the infusions of trimetaphan, measurements of ventilation and echocardiographic assessments of pulmonary vascular tone (DeltaPmax) were made during euoxia and during a short period of isocapnic hypoxia. Subjects were also studied on two control days, when a saline infusion was substituted for trimetaphan. Trimetaphan had no effect on either euoxic ventilation or the sensitivity of ventilation to acute hypoxia. Trimetaphan significantly reduced DeltaPmax in euoxia (P
Robbins, Peter A - One of the best experts on this subject based on the ideXlab platform.
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Lack of involvement of the autonomic nervous system in early ventilatory and pulmonary vascular acclimatization to hypoxia in humans
Blackwell Science Inc, 2006Co-Authors: Liu Chun, Smith, Thomas G, Balanos, George M, Brooks Jerome, Crosby Alexi, Herigstad Mari, Dorrington, Keith L, Robbins, Peter AAbstract:The activity within the autonomic nervous system may be altered following sustained exposure to hypoxia, and it is possible that this increase in activity underlies the early acclimatization of both ventilation and the pulmonary vasculature to hypoxia. To test this hypothesis, seven individuals were infused with the Ganglionic blocker trimetaphan before and after an 8 h exposure to hypoxia. The short half-life of trimetaphan should ensure that the initial infusion does not affect acclimatization to the 8 h hypoxia exposure, and the use of a Ganglion Blocking Agent should inhibit activity within all branches of the autonomic nervous system. During the infusions of trimetaphan, measurements of ventilation and echocardiographic assessments of pulmonary vascular tone (ΔP(max)) were made during euoxia and during a short period of isocapnic hypoxia. Subjects were also studied on two control days, when a saline infusion was substituted for trimetaphan. Trimetaphan had no effect on either euoxic ventilation or the sensitivity of ventilation to acute hypoxia. Trimetaphan significantly reduced ΔP(max) in euoxia (P < 0.05), but had no significant effect on the sensitivity of ΔP(max) to acute hypoxia once changes in cardiac output had been controlled for. The 8 h period of hypoxia elevated euoxic ventilation (P < 0.001) and ΔP(max) (P < 0.001) and increased their sensitivities to acute hypoxia (P < 0.001 for both), indicating that significant acclimatization had occurred. Trimetaphan had no effect on the acclimatization response of any of these variables. We conclude that altered autonomic activity following 8 h of hypoxia does not underlie the acclimatization observed in ventilation or pulmonary vascular tone
Yingzi Lin - One of the best experts on this subject based on the ideXlab platform.
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Chronic central infusion of orexin-A increases arterial pressure in rats.
Brain research bulletin, 2002Co-Authors: Yingzi Lin, Kiyoshi Matsumura, Takuya Tsuchihashi, Isao Abe, Mitsuo IidaAbstract:Abstract We determined the cardiovascular responses as well as food and water intakes to chronic intracerebroventricular administration of orexin-A and orexin-B for 14 days in conscious rats. Chronic intracerebroventricular infusion of orexin-A (50 pmol/h) elicited a significant increase in systolic blood pressure on the third day (+15.6 ± 2.9 mm Hg), and during the continuous intracerebroventricular infusion of orexin-A the blood pressure returned to the baseline levels at day 14. In contrast, chronic intracerebroventricular infusion of orexin-B (50 pmol/h) failed to change systolic blood pressure during the 14 days of experimental periods. Chronic intracerebroventricular infusions of neither orexin-A nor orexin-B changed urinary catecholamine excretions, food and water intakes, and urine volumes at 7 and 14 days of infusion periods. Mean arterial pressure directly measured at 14 days did not differ among the groups of orexin-A, orexin-B, and artificial cerebrospinal fluid treatments. Both intravenous injections of pentolinium (5 mg/kg), a Ganglion Blocking Agent, and CV-11974 (0.05 mg/kg), an AT 1 receptor antagonist, decreased arterial pressure; however, these responses were not different among the groups. These results suggest that central orexin-A participates in the short-term regulation of blood pressure; however, the contributions of central orexins to the long-term regulations of blood pressure, sympathetic nervous system, and appetite may be little.
Okitsu Kenji - One of the best experts on this subject based on the ideXlab platform.
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Effects of sodium sulfate and sodium chloride for sonochemical degradation on1,4-benzoquinone and hydroquinone in aqueous solution
'Penerbit Universiti Kebangsaan Malaysia (UKM Press)', 2018Co-Authors: Uddin, Md. Helal, Okitsu KenjiAbstract:1,4-benzoquinone, with the molecular formula C6H4O2, is generally known as a para-quinone. It is a six-member ring compound with an oxidized derivative known as 1,4-hydroquinone, which is a bright yellow crystal that has an irritating odour. On the other hand, hydroquinone, also known as benzene-1,4-diol, has the chemical formula C6H4(OH)2. It looks like a white granular solid. Quinone is generally used as a precursor to hydroquinone. The skeletal muscle relaxant, Ganglion Blocking Agent, benzoquinonium, is made from benzoquinone. It is utilized to suppress double-bond migrations during olefin metathesis reactions. 1,4-benzoquinone is also used in the synthesis of Bromodol, while hydroquinone is the main ingredient in black-and-white photographic developers such as film and paper developers, where it diminishes the silver halide to elemental silver. There are various other uses related to this diminishing power. As a polymerization inhibitor, hydroquinone prevents the polymerization of methyl methacrylate, acrylic acid, etc. Studies have demonstrated the various effects of Na2SO4 and NaCl on the sonochemical degradation of 1,4-benzoquinone and hydroquinone using a 200-kHz sonicator. The highest degradation rate was obtained in the presence of 0.433 M Na2SO4 for 1,4-benzoquinone. After 30 minutes of ultrasonic irradiation, the total concentration of 1,4-benzoquinone decreased to 99% in the presence 0.433 M Na2SO4. Without Na2SO4, the sonochemical degradation rate of 1,4-benzoquinone was 4.5 times higher than that of hydroquinone, whereas in the presence of 0.433 M Na2SO4 under the same conditions the initial reaction rate of 1,4-benzoquinone was increased to become 10.6 times higher than that of hydroquinone. On the other hand, in the presence of NaCl, no effects were observed for the decomposition of hydroquinone but negative effects were clearly observed for the decomposition of 1,4-benzoquinone
