title: 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.affiliation: Institute for Drug Discovery Research, Yamanouchi Pharmaceutical, Tsukuba, Japan. tahara@yamanouchi.co.jp
authors.forename: Atsuo
authors.initials: A
authors.lastname: Tahara
authors.forename: Junko
authors.initials: J
authors.lastname: Tsukada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tomura
authors.forename: Koh-ichi
authors.initials: K
authors.lastname: Wada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kusayama
authors.forename: Noe
authors.initials: N
authors.lastname: Ishii
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Yatsu
authors.forename: Wataru
authors.initials: W
authors.lastname: Uchida
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Taniguchi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D008297:Male; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017483:Receptors, Vasopressin / Q000378:metabolism*
chemical_list: D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin