Sexual dimorphism in renal vascular reactivity to ang1otensin in spontaneously hypertensive rats: Effects of gonadectomy and estrogen replacement Academic Article uri icon


  • In the spontaneously hypertensive rat (SHR), hypertension develops to a greater extent in males (M) than in females (F). To determine the roles of the renal vasculalure and gonadal steroids in this sexual dimorphism in hypertension, Ihe effects of gonadectomy on renal vascular reactivity to angiotensin (ANG II) were examined in M and F SHR and normotensive-control rats (WKY). The effects of estrogen replacement (ER) in F WKY and SHR were also examined. Age-matched M and F WKY and SHR were gunadectomized (GnX) or sham-GnX (intact, INT) at 4 wks age. At 7 wks age, GnX F WKY and SHR either received ER (I7 estradiol, 0.1 mg pellet) or remained untreated. At 9-10 wks age, left kidneys from M and F (INT and GnX) WKY and SHR were isolated and perfused (wiih Krebs-Henseleil-bicarb- constant flow), and a dose-response (A mmHg) to ANG II (0.0001 0.05 nmoles) obtained. Data are means SE (n = 8-9 rats per expmtl. group). In INT rats, maximal reactivity in WKY was greater in M (141 7 mmHg) than in F (99 ]y, reactivity in SHR was similar in M (164 6 mmHg) and F (174 15). Thus, in INT F, maximal reactivity increased markedly in SHR vs. WKY ( 174 15 vs. 99 11), while in INT M, reactivity increased moderately in SHR vs. WKY (164 6 vs. 141 7). GnX in M did not alter maximal reactivity uf WKY (128 10 mmHg) or SHR (164 5); however, GnX in F potentiated reactivity in WKY (133 7 mmHg), but attenuated reactivity in SHR (149 7). In GnX F rats, ER restored maximal reactivity in SHR (171 7 mmHg), but paradoxically enhanced reactivity in WKY (149 5). These data suggest that: I) endogenous estrogen, but not testosterone, exerts important modulalory effects on renal vascular reactivity to ANG II in WKY and SHR; and 2) exogenous estrogen alone is sufficient to restore normal vascular reactivity in SHR hut not in WKY.

published proceedings

  • FASEB Journal

author list (cited authors)

  • Burton, R. D., & Stallone, J. N.

complete list of authors

  • Burton, RD||Stallone, JN

publication date

  • January 1996