Testosterone enhances estradiol's cardioprotection in ovariectomized rats

Abstract

After menopause, the development of cardiovascular disease (CVD) is due not only to estrogen decline but also to androgen decline. This study examined the effects of either estradiol (E 2 ) or testosterone replacement alone or E 2 -testosterone combination on isolated myocytes in ovariectomized (Ovx) rats subjected to ischemia/reperfusion (I/R). Furthermore, we determined whether the effects are associated with b 2 -adrenoceptor (b 2 -AR). Five groups of adult female Sprague-Dawley rats were used: Sham operation (Sham) rats, bilateral Ovx rats, Ovx rats with E 2 40 mg/kg per day (OvxCE), Ovx rats with testosterone 150 mg/kg per day (OvxCT), and Ovx rats with E 2 40 mg/kg per dayC testosterone 150 mg/kg per day (OvxCE/T). We determined the lactate dehydrogenase (LDH) release, percentage of rod-shaped cells and apoptosis of ventricular myocytes from rats of all groups subjected to I/R. Then, we determined the above indices and contractile function with or without a selective b 2 -AR antagonist ICI 118 551. We also determined the expression of b 2 -AR. Our data show that either E 2 or testosterone replacement alone or E 2 and testosterone in combination decreased the LDH release, increased the percentage of rod-shaped cells, reduced apoptotic cells (%), and combination treatment appeared to be more effective than either E 2 or testosterone replacement alone. ICI 118 551 abolished the effects of the three. Combination supplementation also enhanced the expression of b 2 -AR. We concluded that in Ovx rats, testosterone enhances E 2 's cardioprotection, while E 2 and testosterone in combination was more effective and the protective effects may be associated with b 2 -AR. The study highlights the potential therapeutic application for CVD in postmenopausal women.

Association of testosterone with estrogen abolishes the beneficial effects of estrogen treatment by increasing ROS generation in aorta endothelial cells

“…The dose of testosterone used for hormonal treatments in postmenopausal women has been widely discussed. Studies have described that low doses (150 g/day) of testosterone can contribute to the cardioprotection in OVX rats by E 2 (29). Another group has described that 300 g of testosterone twice/week improves insulin sensitivity and muscle strength in elderly women with chronic heart failure (25).…”

High Concentration of Epigallocatechin‐3‐Gallate Increased the Incidences of Arrhythmia and Diastolic Dysfunction Via β2‐adrenoceptor

“…Myocytes contraction was measured as previously described by our laboratory (Jiang and others ; Liu and others ). Briefly, myocytes were superfused with KH solution.…”

The different role of sex hormones on female cardiovascular physiology and function: not only oestrogens

“…In a recent work, Liu et al . demonstrated that the addition of a physiological dose of testosterone to oestrogen therapy enhances the cardio‐protection of E2 in OVX rat cardiomyocytes subjected to ischaemia/reperfusion. Combined E2 and testosterone supplementation reduced myocardial injury, increased viability, and improved contractile function through the activation of a common signalling pathway: PI3K–AKT via beta2‐AR .…”