Sexual dimorphism in regional blood flow responses to vasopressin in conscious rats.
The greater pressor response to vasopressin in male than in nonestrous female rats results from a greater increase in total peripheral resistance in males. The present study was performed to identify the vascular beds that contribute to this difference. Mean arterial blood pressure (MABP) and changes in blood flow in the mesenteric and renal arteries and terminal aorta were measured in conscious male and nonestrous female rats 3 h after surgery. Graded intravenous infusions of vasopressin induced greater increases in MABP and mesenteric vascular resistance and a greater decrease in mesenteric blood flow in males. Vasopressin also increased renal vascular resistance to a greater extent in males. Because renal blood flow remained unchanged, this difference may be due to autoregulation. The vasopressin-induced reduction in blood flow and increased resistance in the hindquarters were moderate and did not differ between sexes. Thus the greater vasoconstrictor response to vasopressin in the mesenteric vascular bed of male than nonestrous females contributed importantly to the sexually dimorphic pressor response to vasopressin in these experiments.
Wang
Y X
YX
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163, USA.
Crofton
J T
JT
Bealer
S L
SL
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D000818:Animals; D001127:Arginine Vasopressin / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006614:Hindlimb / Q000098:blood supply; D007262:Infusions, Intravenous; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects*; D012077:Renal Artery / Q000187:drug effects / Q000502:physiology; D012079:Renal Circulation / Q000187:drug effects; D012727:Sex Characteristics; D013152:Splanchnic Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D001127:Arginine Vasopressin