Serca2a and Na+/Ca2+ exchanger are involved in left ventricular function following cardiac remodelling of female rats treated with anabolic androgenic steroid

Low and high doses of oxandrolone promote pathological cardiac remodeling in young male rats

Oxandrolone (OXA) used in clinical practice, however, its misuse is frequent, including by adolescents pursuing an aesthetic goal. However, the impacts of noxious doses on the cardiovascular system remain unknown.

AIM

To investigate cardiac effects of OXA in low (LD) and high (HD) doses.

METHODS

Male Wistar prepubescent rats were separated into 3 experimental groups: control (CON), LD, and HD. Only the CON group received the carrier (carboxymethylcellulose, 0.5%), while the LD and HD groups received, respectively, 2.5 and 37.5 mg/kg/day of OXA via gavage for 4 weeks. The hemodynamic parameters (+dP/dtmax, -dP/dtmin, and Tau) and cardiac autonomic tonus were assessed. Hearts were retrieved for histological analyses and oxidative stress evaluation. Expression levels of calcium-handling proteins were measured by western blot.

RESULTS

The OXA treatment changed neither the cardiac contractility nor the cardiac autonomic tonus. However, cardiac hypertrophy, collagen deposition, and increased angiotensin-converting enzyme (ACE) expression were observed in a dose-dependent way. Also, the p-phospholamban (p-PLB)/PLB ratio was observed to decrease and increase, respectively, in the LD and HD groups; the sarcoplasmic/endoplasmic reticulum calcium ATPase 2a (SERCA2a)/PLB ratio being higher in both groups. OXA increased SOD1 expression and decreased catalase expression only in the LD group, and protein oxidation was increased in HD.

CONCLUSION

Both doses of OXA could promote pathological cardiac remodeling, probably via increased ACE, and these effects were exacerbated in the HD treatment, but cardiac contractility was not affected regardless of the dose.

Involvement of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) in mPRα (PAQR7)-mediated progesterone induction of vascular smooth muscle relaxation

Progesterone acts directly on vascular smooth muscle cells (VSMCs) through activation of membrane progesterone receptor α (mPRα)-dependent signaling to rapidly decrease cytosolic Ca²⁺ concentrations and induce muscle relaxation. However, it is not known whether this progesterone action involves uptake of Ca²⁺ by the sarco/endoplasmic reticulum (SR) and increased sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) activity. The present results show that treatment of cultured human VSMCs with progesterone and the selective mPR agonist Org OD-02-0 (OD 02-0) but not with the nuclear PR agonist R5020 increased SERCA protein expression, which was blocked by knockdown of mPRα with siRNA. Moreover, treatments with progesterone and OD 02-0, but not with R5020, increased phospholamban (PLB) phosphorylation, which would result in disinhibition of SERCA function. Progesterone and OD 02-0 significantly increased Ca²⁺ levels in the SR and caused VSMC relaxation. These effects were blocked by pretreatment with cyclopiazonic acid (CPA), a SERCA inhibitor, and by knockdown of SERCA2 with siRNA, suggesting that SERCA2 plays a critical role in progesterone induction of VSMC relaxation. Treatment with inhibitors of inhibitory G proteins (Gi, NF023), MAP kinase (AZD 6244), Akt/Pi3k (wortmannin), and a Rho activator (calpeptin) blocked the progesterone- and OD 02-0-induced increase in Ca²⁺ levels in the SR and SERCA expressions. These results suggest that the rapid effects of progesterone on cytosolic Ca²⁺ levels and relaxation of VSMCs through mPRα involve regulation of the functions of SERCA2 and PLB through Gi, MAP kinase, and Akt signaling pathways and downregulation of RhoA activity.NEW & NOTEWORTHY The rapid effects of progesterone on cytosolic Ca²⁺ levels and relaxation of VSMCs through mPRα involve regulation of the functions of SERCA2 and PLB through Gi, MAP kinase, and Akt signaling pathways and downregulation of RhoA activity.

Eight weeks of treatment with nandrolone decanoate in female rats promotes disruption in the redox homeostasis and impaired renal function

INTRODUCTION

Misuse of AAS is emergent among both genders, however, few studies were performed evaluating AAS effects on female body and none evaluate the impact of nandrolone decanoate (ND) in renal function.

AIM

Determine the effects of chronic treatment with ND on kidney function of female rats and evaluate the influence of oxidative stress on it.

MATERIAL AND METHODS

Female rats were separated into two groups (n = 8 each), the treated group (DECA), which received ND at a dose of 20 mg/kg/week (i.m), and the control group (C), which was treated with the vehicle (peanut oil, i.m.). All treatments were performed during eight weeks. After this period, 24 h urine, blood and organs (heart, gastrocnemius muscle, liver and kidney) were collected. Organ hypertrophy was calculated, and kidney collagen content was evaluated. AOPP, TBARS, SOD and catalase activity were determined in the kidney. Moreover, proteinuria and creatinine clearance were also investigated.

KEY-FINDINGS

Hypertrophy was observed in the liver, gastrocnemius muscle, heart and kidney. Kidney hypertrophy was followed by a reduced organ function and an increase in collagen deposition. Oxidative stress upsurge occurred in both proteins and lipids, followed by a reduction in SOD activity.

SIGNIFICANCE

Administration of DN in rats was followed by renal damage and kidney fibrosis due to increased oxidative stress on that organ.