Central vasopressin in the modulation of catecholamine release in conscious rats
| Autor: | Gordon Mackie, Catherine C.Y. Pang, Kathryn A. King, Richard A. Wall |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Vasopressin Baroreceptor Epinephrine Physiology Neuropeptide Blood Pressure Norepinephrine Catecholamines Physiology (medical) Internal medicine medicine Animals Injections Intraventricular Pharmacology urogenital system Chemistry Solitary nucleus Antagonist Rats Inbred Strains General Medicine Rats Arginine Vasopressin Endocrinology nervous system Hypothalamus Reflex Catecholamine hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 63:1501-1505 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y85-247 |
| Popis: | Neurons containing arginine vasopressin (AVP) have been shown to project from the paraventricular nucleus of the hypothalamus to the nucleus tractus solitarius (NTS) in the medulla. We investigated whether AVP acts in brain stem regions to influence sympathoadrenal outflow. Cannulae were implanted into the fourth ventricle of rats 7 days prior to the experiment. The effects of intracerebroventricular (icv) injections of AVP, the vehicle, and AVP antagonist, d(CH2)5Tyr(Me)AVP, on mean arterial pressure (MAP) and plasma noradrenaline (NA) and adrenaline (A) levels were determined in conscious unrestrained rats. Injections of AVP (icv, 23 and 73 ng/kg) but not the vehicle increased MAP and plasma NA and A levels. In contrast, iv injection of AVP increased MAP but decreased plasma concentrations of A and NA. The pressor response to icv injection of AVP was abolished by prior icv injection of AVP antagonist. Injection of AVP antagonist (icv, 0.5 and 1.5 μg/kg) had no effect on MAP or plasma NA or A levels. These results show that centrally injected AVP activates sympathoadrenal outflow, possibly via an inhibition of baroreceptor reflexes. Since centrally administered AVP antagonist did not influence MAP or plasma NA or A levels, it appears that endogenously released AVP does not have a tonic influence on central cardiovascular reflex system in conscious, unrestrained rats. |
| Databáze: | OpenAIRE |
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