title: Gender differences in hemodynamic responses to endothelin-1.
abstract: We investigated whether gender affects the pressor and constrictor effects of endothelin-1 (ET-1) in anesthetized rats. Baseline values for arterial blood pressure (mmHg) and hindquarter resistance (HQR, mmHg/ml/min/100 g), respectively, were similar in male (96.0 +/- 3.1 and 13.9 +/- 0.6) and female (103.1 +/- 5.6 and 12.8 +/- 2.3) rats. ET-1 (1 and 3 microg/kg) produced rapid and transient falls in arterial blood pressure and HQR, followed by long-lasting increases in blood pressure and HQR. The initial ET-1-induced hypotension and vasodilation were similar in both groups. However, the pressor and hindquarter vasoconstrictor effects were significantly higher (p < 0.05) in male than female rats. Thus, the increases in blood pressure and HQR to ET-1 (3 microg/kg) were attenuated in female (+15.3 +/- 3.4 mmHg and +3.7 +/- 1.6 mmHg/ml/min/100 g) compared to male (+24.9 +/- 2.3 mmHg and +8.0 +/- 1.6 mmHg/ml/ min/100 g) rats. These results indicate that there is a gender difference in the vasoconstrictor, but not the vasodilator effects of ET-1. We suggest that the lower ET-1-induced hypertension and hindlimb vasoconstrictions observed in female rats may be responsible for the lower risk of developing coronary heart disease in premenopausal women.
authors.affiliation: Department of Physiology, Laval University Hospital Research Center, Ste-Foy, Québec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Tatchum-Talom
authors.forename: C
authors.initials: C
authors.lastname: Martel
authors.forename: C
authors.initials: C
authors.lastname: Labrie
authors.forename: F
authors.initials: F
authors.lastname: Labrie
authors.forename: A
authors.initials: A
authors.lastname: Marette
mesh_terms: D000818:Animals; D019332:Endothelin-1 / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics
chemical_list: D019332:Endothelin-1