| Project/Area Number |
63480118
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
環境生理学(含体力医学･栄養生理学)
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| Research Institution | University of Occupational and Environmental Health, Japan |
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Principal Investigator |
YAMASHITA Hiroshi UOEH, Physiology, Professor, 医学部, 教授 (00030841)
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| Co-Investigator(Kenkyū-buntansha) |
OSAKA Toshimasa UOEH, Physiology, Assistant, 医学部, 助手 (30152101)
INENAGA Kiyotoshi UOEH, Physiology, Lecturer, 医学部, 講師 (90131903)
KANNAN Hirohi UOEH, Physiology, Associate professor, 医学部, 助教授 (00049058)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Brain slice preparation / Neuropeptides / Neurosecretory neuron / Anestetized cat and rat / Neural network / Conscious rat / Renal sympathetic nerve activity |
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| Research Abstract |
1. BRat hypothalamic slice preparation :
(1) Atrial Natriuretic Polypeptide (ANP) depressed Angiotensin II (AII) induced excitation of neurons in the Subfornical Organ(SFO).
(2) Cortisol had an inhibitory effect on neurons in the parvocellular division of the Paraventricular Nucleus (PVN) in adrenalectomized rats.
(3) TRH excited PVN neurons. PVN neurons were sensitive to TRH at low concentration (10^<-10>M)
(4) Kappa-selective opioid receptor agonist inhibited both Vasopressin (AVP) and Oxytocin (OT) neurons, while delta- and mu-receptor agonists inhibited selectively OT neurons in the supraoptic nucleus (SON).
(5) Brain natriuretic peptide inhibited AVP neurons in the SON and in the region of the anteroventral Third Ventricle (AV3V).
2. BAnalysis of neural network involved in water homeostasis and effects of neuropeptides under anestetized cats and rats :
(1) Activation of the POMn, OVLT, and the SFO neurons mainly inhibited the PVN neurons in the cat.
(2) Thirty percent of both neurosecretory and non-neurosecretory neurons in the PVN were osmosensitive in the rat.
(3) Activation of vagal gastric afferents excited OT neurons and inhibited AVP neurons in the rat PVN. And central noradrenergic projection is involved in the gastric afferent pathway.
3. Effects of centrally administered neuropeptides on sympathetic nerve activity in conscious rats :
(1) Intracerebroventricular (i. c. v.) administration of AII evoked an increase in arterial blood pressure (ABP) and decreases in Heart Rate (HT) and Renal Sympathetic Nerve Activity (RSNA).
(2) The pressure response induced by i. c. v. AII was attenuated by prior i. c. v. administration of ANP but no significant effects of ANP was observed on the bradycardia and inhibition of RSNA by i. c. v. AII.
(3) I. c. v. administration of endothelin evoked an increase in ABP and decrease in HR and RSNA.
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