Lack Of Progesterone Impairs Endothelium-dependent Vascular Relaxation Of Pulmonary Arteries Of Female Rats Which Is Associated With ENOS Uncoupling

Objective: Progesterone and estrogen,essential to the female,are primary hormones synthesized by the ovaries and some studies show that they have some physiological effects on pulmonary arterial function.Our study is objected to investigate the effects and theories of progesterone and estrogen on pulmonary arteries and what role eNOS(endothelial nitric oxide synthase)plays among them.Methods: The expression of eNOS and endothelium-dependent vasodilation function of pulmonary arteries were detected in progesterone receptor antagonist(RU486)treated female rats and ovariectomized(OVX)rats which were administrated with one or two of saline,estradiol,progesteron and Sapropterin dihydrochloride(6RBH4)respectively.Results: The results manifested that the expression of eNOS increased when progesterone rather than estrogen was antagonized or reduced;nevertheless,endothelium-dependent vasodilation function of pulmonary arteries was injured.Moreover,our study manifested that6RBH4 could reverse these effects and maintain the ordinary vasodilation ability of pulmonary arteries.Conclusion: Lack of progesterone,instead of estrogen,impaired endothelium-dependent vasodilation function of pulmonary arteries,which is related to eNOS uncoupling.Therefore,progesterone plays a key role in keeping a normal state of pulmonary arteries of female rats.