Microvascular effects of corticotropin-releasing hormone in human skin vary in relation to estrogen concentration during the menstrual cycle.
Females have a significantly greater life expectancy than males, which in part may be due to the cardio-protective effects of the female sex hormone, estrogen, on vascular function. However, the sex-specific mechanisms contributing to these differences are complex and not fully understood. Previously we have reported that corticotropin-releasing hormone (CRH) has potent dilator effects in the female skin circulation via mast cell degranulation. Furthermore the dilator response to CRH was more enhanced in females than in age-matched males, suggesting that estrogens may be involved. In this study we examined whether CRH-induced dilation and endothelial cell-dependent dilation in the skin circulation of pre-menopausal females were associated with changes in estrogen during the menstrual cycle. CRH-induced dilation (1 nM) was enhanced in the presence of high circulating concentrations of estrogen and a positive correlation was identified between CRH-induced dilation and plasma estrogen concentrations. Endothelial cell-dependent dilation was examined using acetylcholine. Acetylcholine-induced dilation (1 nM) was not correlated with circulating concentrations of estrogen. These data suggest the variation in CRH-induced dilation in the skin microvasculature during the menstrual cycle may be due to estrogenic effects on mast cell function and not due to direct changes in endothelial cell function.
Mothers and Babies Research Center, Hunter Medical Research Institute, Newcastle, New South Wales, Australia.
V L
VL
Clifton
R
R
Crompton
M A
MA
Read
P G
PG
Gibson
R
R
Smith
I M R
IM
Wright
D000109:Acetylcholine / Q000097:blood / Q000494:pharmacology; D000328:Adult; D003346:Corticotropin-Releasing Hormone / Q000097:blood / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004967:Estrogens / Q000097:blood*; D005260:Female; D005542:Forearm; D006801:Humans; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008597:Menstrual Cycle / Q000097:blood*; D008833:Microcirculation / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation
D004967:Estrogens; D003346:Corticotropin-Releasing Hormone; D000109:Acetylcholine