Long-term treatment with Nandrolone Decanoate impairs mesenteric vascular relaxation in both sedentary and exercised female rats.

Nandrolone Decanoate (ND) is an Anabolic Androgenic Steroid (AAS) that under abusive regimen can lead to multiple physiological adverse effects. Studies of AAS-mediated cardiovascular (CV) alterations were mostly taken from male subjects, even though women are also susceptible to the effects of AAS and gender-specific differences in susceptibility to vascular diseases exist. Here we investigate ND-induced vascular reactivity alterations in both sedentary and exercised female rats and whether these alterations depend on endothelium-derived factors. We show that chronic exposure of female Wistar rats to ND (20mg/Kg/week for 4weeks) impaired the vascular mesenteric bed (MVB) reactivity to vasodilator (acetylcholine) agonist. The endothelium-dependent Nitric Oxide (NO) component was reduced in ND-treated rats, whereas neither the endothelium-derived hyperpolarizing factor (EDHF) component nor prostanoids were altered in the MVBs. Endothelial dysfunction observed in ND-treated rats was associated with decreased eNOS (Ser1177) and Akt (Ser473) phosphorylation sites and upregulation of iNOS and NADPH oxidase expression. Exercise training by weight lifting in water did not improve the vascular alterations induced by ND treatment. ND treatment also significantly reduced the serum levels of estradiol in females, overriding its CV protective effect. These results help uncover the role of ND modulating endothelial function in the setting of CV disease caused by the abuse of AAS in females. If this translates to humans, young women abusing AAS can potentially lose the cardio protective effect rendered by estrogen and be more susceptible to CV alterations.

Low dose of methyltestosterone in ovariectomised rats improves baroreflex sensitivity without geno- and cytotoxicity.

This study evaluated the effects of the isolated use of a low dose of methyltestosterone (MT) on cardiovascular reflexes and hormonal levels and its geno- and cytotoxic safety in ovariectomized rats. Female Wistar rats were divided into four groups (n = 6), respectively: SHAM (received vehicle methylcellulose 0.5%), SHAM + MT (received MT 0.05 mg/kg), OVX (received vehicle), and OVX + MT (received MT). Twenty-one days after ovariectomy, treatment was given orally daily for 28 days. The Bezold-Jarisch reflex (BJR) was analyzed by measuring the bradycardic and hypotensive responses elicited by phenylbiguanide (PBG) administration. The baroreflex sensitivity (BRS) was evaluated by phenylephrine and sodium nitroprussite. Myocyte hypertrophy was determined by morphometric analysis of H&E stained slides. Biochemical data were analyzed, as well as micronucleus assay. MT improved BRS and increased testosterone values, but did not change estradiol in the OVX group. MT did not promote changes in mean arterial pressure, heart rate, BJR, serum concentrations of troponin I, weight and histopathology of the heart. MT was able to restore the BRS in OVX rats. The geno- and cytotoxic safety of the MT was demonstrated by the absence of an increase in the micronucleus (PCEMN) or change in the ratio between normochromatic erythrocytes and polychromatic erythrocytes (NCE/PCE).