Effect of gender on endothelium-dependent dilation to bradykinin in human adipose microvessels.
We examined the influence of gender and climacteric status, two coronary risk factors, on bradykinin (BK)-induced dilation in adipose arterioles from men and women of different ages [premenopausal women (Pre-W), postmenopausal women (Post-W), and similar aged men (Y-M and O-M), respectively]. We examined the responses from both omental (more closely associated with coronary disease) and subcutaneous fat. Tissues were obtained at surgery and cannulated (60 mmHg) for measurement of internal diameter. In vessels from omental tissue, dilation to BK was more sensitive in Pre-W than other groups, whereas in vessels from subcutaneous tissue, sensitivity to BK was greater in both Pre-W and Post-W compared with Y-M and O-M. Maximal dilation was similar among groups. Indomethacin (Indo; 10(-5) M) alone had no effect on dilation to BK in any groups, but Indo and N(omega)-nitro-L-arginine methyl ester (L-NAME; 10(-4) M) reduced dilation to BK in Pre-W more than in Y-M. L-NAME increased dilation to BK in subcutaneous fat from Y-M but had no effect in Post-W and O-M. Indo- and L-NAME-resistant dilation in all vessels was markedly reduced by 30 mM KCl. There was no difference in sodium nitroprusside-induced dilation among groups. We conclude that gender and climacteric state contribute to mechanisms of microvascular regulation in humans. Functional vascular differences in visceral and subcutaneous fat may underlie the proposed differential influence of these tissues on cardiovascular risk.
Department of Internal Medicine, Cardiovascular Research Center, and Veterans Administration Medical Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Atsushi
A
Sato
Hiroto
H
Miura
Yanping
Y
Liu
Lewis B
LB
Somberg
Mary F
MF
Otterson
Michael J
MJ
Demeure
William J
WJ
Schulte
Luann M
LM
Eberhardt
Fausto R
FR
Loberiza
Ichiro
I
Sakuma
David D
DD
Gutterman
D000273:Adipose Tissue / Q000098:blood supply*; D000328:Adult; D001920:Bradykinin / Q000494:pharmacology*; D002979:Climacteric / Q000502:physiology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009852:Omentum / Q000098:blood supply; D012737:Sex Factors; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D001920:Bradykinin; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin