17Beta-estradiol stimulates flow-induced vasodilatation in isolated small mesenteric arteries from prepubertal femal rats.
OBJECTIVE
Flow-induced vasodilatation may contribute to lowering of peripheral resistance to pregnancy. This study investigated modulation of flow responses by 17beta-estradiol.


METHODS
Small mesenteric arteries from prepubertal female Wistar rats were pretreated for 3 hours with 17beta-estradiol (10(-7) mol/L) with 17alpha-estradiol (10(-7) mol/L) or vehicle (0.1% dimethylsulfoxide). Responses to intraluminal flow were evaluated with use of a pressure arteriograph.


RESULTS
After pretreatment with 17beta-estradiol arteries relaxed to flow, whereas those treated with vehicle or 17alpha-estradiol did not (percent change in diameter at maximum flow rate after 17beta-estradiol 38.7% +/- 5.7%, n = 10, vs 1.1% +/- 4.3%, n = 10 after vehicle; p < 0.01). Endothelium removal or pretreatment with either a nitric oxide synthase inhibitor or a novel soluble guanylyl cyclase inhibitor diminished the response to 17beta-estradiol.


CONCLUSIONS
17Beta-estradiol stimulated nitric oxide-mediated flow-induced relaxation. Through this pathway 17beta-estradiol could play an important role in the control of vascular tone.
Cockell
A P
AP
Division of Obstetrics and Gynecology, United Medical and Dental Schools of Guy's and St. Thomas' Hospitals, London, United Kingdom.
Poston
L
L
D000818:Animals; D004730:Endothelium, Vascular / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D013314:Stress, Mechanical; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
D009569:Nitric Oxide; D004958:Estradiol