Alterations of renal vasopressin V1A and V2 receptors in spontaneously hypertensive rats.

Abstract

To elucidate the role of arginine vasopressin (AVP) in a hypertensive state, the characteristics of renal cortex V(1A) and medulla V(2) receptors in young spontaneously hypertensive rats (SHR) during the developmental phase of hypertension were compared with those of age-matched Wistar-Kyoto (WKY) rats using the radioligand receptor assay technique. The systolic blood pressure of 8-week-old SHR was statistically significantly higher than that of WKY rats (142 +/- 1 vs. 125 +/- 2 mm Hg). The plasma AVP levels were also significantly higher in SHR than in WKY rats (3.20 +/- 0.41 vs. 1.96 +/- 0.34 pg/ml). In SHR, the maximum capacity of (3)H-d(CH(2))(5)Tyr(Me)AVP binding to cortical V(1A) receptors (B(max)) was statistically significantly higher than that of WKY rats (39.7 +/- 2.7 vs. 22.4 +/- 0.9 fmol/mg protein). Furthermore, the B(max) values of (3)H-AVP binding to medullary V(2) receptors in SHR were also significantly higher than in WKY rats (40.2 +/- 1.9 vs. 28.3 +/- 1.3 fmol/mg protein). However, the apparent dissociation constant (K(d)) values of renal cortex V(1A) and medulla V(2) receptors in SHR and WKY rats were not significantly different. These results indicate that increased amounts of renal cortex V(1A) and medulla V(2) receptors in SHR play an important role in the pathophysiology of hypertension.

• Authors: Atsuo Tahara, Junko Tsukada, Yuichi Tomura, Koh-ichi Wada, Toshiyuki Kusayama, Noe Ishii, Takeyuki Yatsu, Wataru Uchida, Nobuaki Taniguchi, Akihiro Tanaka
• Journal: Pharmacology (Pharmacology) Vol. 67 Issue 2 Pg. 106-12 (Feb 2003) ISSN: 0031-7012 [Print] Switzerland
• PMID: 12566855 (Publication Type: Comparative Study, Journal Article)
• Copyright: Copyright 2003 S. Karger AG, Basel

Chemical References

• Receptors, Vasopressin
• Arginine Vasopressin

Topics

• Animals
• Arginine Vasopressin (metabolism)
• Dose-Response Relationship, Drug
• Hypertension (metabolism)
• Kidney (metabolism)
• Kidney Cortex (metabolism)
• Kidney Medulla (metabolism)
• Male
• Protein Binding (physiology)
• Rats
• Rats, Inbred SHR
• Rats, Inbred WKY
• Receptors, Vasopressin (metabolism)