Myocardial antioxidant and oxidative stress changes due to sex hormones

Abstract

The purpose of the present study was to examine myocardial antioxidant and oxidative stress changes in male and female rats in the presence of physiological sex hormone concentrations and after castration. Twenty-four 9-week-old Wistar rats were divided into four groups of 6 animals each: 1) sham-operated females, 2) castrated females, 3) sham-operated males, and 4) castrated males. When testosterone and estrogen levels were measured by radioimmunoassay, significant differences were observed between the castrated and control groups (both males and females), demonstrating the success of castration. Progesterone and catalase levels did not change in any group. Control male rats had higher levels of glutathione peroxidase (50%) and lower levels of superoxide dismutase (SOD, 14%) than females. Control females presented increased levels of SOD as compared to the other groups. After castration, SOD activity decreased by 29% in the female group and by 14% in the male group as compared to their respective controls. Lipid peroxidation (LPO) was assessed to evaluate oxidative damage to cardiac membranes by two different methods, i.e., TBARS and chemiluminescence. LPO was higher in male controls compared to female controls when evaluated by both methods, TBARS (360%) and chemiluminescence (46%). Castration induced a 200% increase in myocardial damage in females as determined by TBARS and a 20% increase as determined by chemiluminescence. In males, castration did not change LPO levels. These data suggest that estrogen may have an antioxidant role in heart muscle, while testosterone does not.

Gender difference in the development of cardiac lesions following acute ischemic-reperfusion renal injury in albino rats

“…Also, cardiac tissue antioxidant enzymes were significantly lower in Ovx group than in control female group, and in Ovx+I/R group than in all other female groups. These results are in line with Barp et al (2002) and Kim et al (1998). On the other hand, Barp et al (2002) found that myocardial CAT activity was not significantly different between control male and female groups.…”

“…These results are in line with Barp et al (2002) and Kim et al (1998). On the other hand, Barp et al (2002) found that myocardial CAT activity was not significantly different between control male and female groups. However, no other study investigated the differences in cardiac injury markers after renal I/R injury between males and females.…”

Testosterone suppresses oxidative stress via androgen receptor-independent pathway in murine cardiomyocytes

“…These observations provide evidence that testosterone deficiency contributes to the deterioration of antioxidant defense mechanisms in cardiomyocytes. In this respect, the results of our study are consistent with those reported by Barp et al (24) and Kłapcińska et al (25) in hearts and Meydan et al (23) in the hippocampal tissue. Data regarding the potential antioxidant role of exogenous testosterone in the heart are very scarce, and conflicting results have been observed in different tissues.…”

Estrogen Protects against Oxidative Multiorgan Damage in Rats with Chronic Renal Failure

“…E. CRF + E 2 male group: reconstitution of central vein (**), mild congestion in chain reactions [13,14] and protect against atherosclerosis by binding free radicals. [40] Being a fat-soluble hormone, estrogen can contribute to membrane fluidity by direct interactions with phospholipids and attenuate the peroxidation of vascular smooth muscle cells and peroxidationinduced cell growth and migration. [41] On the other hand, age-related decline in estrogen secretion is accompanied by excessive oxidative stress and peroxidative cell damage, [42] which are known features of CRF.…”