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Vasopressin receptors and inositol trisphosphate production in blood vessels of spontaneously hypertensive rats.
- Source :
-
Canadian journal of physiology and pharmacology [Can J Physiol Pharmacol] 1989 Mar; Vol. 67 (3), pp. 232-9. - Publication Year :
- 1989
-
Abstract
- To understand the regulation of vasopressin (AVP) receptors in spontaneous hypertension, we investigated the pressor response of AVP in the perfused mesenteric vasculature, AVP binding sites in the membrane preparation of the same vascular bed, and the production of inositol trisphosphate (InsP3) stimulated by AVP in the aorta of spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY), and Wistar rats (WR) at different ages (4-16 weeks). Plasma AVP concentrations were similar in SHR, WKY, and WR at all ages. The density of AVP vascular binding sites was significantly higher in WKY than in SHR and WR at 12 weeks. Receptor affinity was similar in all strains. The pressor response of the mesenteric vasculature to AVP was similar in the three strains of rats at 4 weeks (prehypertensive stage) and increased progressively in SHR compared with WKY and WR at 8 and 12 weeks of age by 43 and 35%, respectively, and by more than 80% at 16 weeks of age (established hypertensive stage). There was no difference in vascular sensitivity to AVP. A significantly increased pressor response to a supramaximal dose of norepinephrine was also found at 16 weeks in SHR, but not in younger rats. InsP3 production in the aorta in response to AVP was increased in SHR at 8, 12, and 16 weeks, compared with WKY and WR. These results suggest that the vascular response to AVP is increased in SHR, in spite of decreased or normal density of binding sites compared with WKY or WR.(ABSTRACT TRUNCATED AT 250 WORDS)
- Subjects :
- Animals
Aorta, Thoracic drug effects
Aorta, Thoracic metabolism
Arginine Vasopressin blood
Arginine Vasopressin metabolism
Body Weight drug effects
Cell Membrane drug effects
Cell Membrane metabolism
Male
Mesenteric Arteries drug effects
Norepinephrine pharmacology
Rats
Rats, Inbred SHR
Rats, Inbred Strains
Rats, Inbred WKY
Receptors, Vasopressin
Blood Pressure drug effects
Hypertension physiopathology
Inosine Nucleotides biosynthesis
Inosine Triphosphate biosynthesis
Receptors, Angiotensin metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0008-4212
- Volume :
- 67
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Canadian journal of physiology and pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 2525949
- Full Text :
- https://doi.org/10.1139/y89-039