Anabolic steroid excess promotes hydroelectrolytic and autonomic imbalance in adult male rats: Is it enough to alter blood pressure?

•AS excess elicited kidney hypertrophy and increased renal AT1R mRNA levels.•AS excess increased Na+/water retention, K+ excretion, and plasma osmolarity.•Water and NaCl intake were distinctly altered by AS excess.•AS-induced autonomic imbalance was attenuated by icv losartan. The present study investigated the effects of anabolic steroid (AS) excess on blood pressure regulation. Male Wistar rats were treated with nandrolone decanoate (AS) or vehicle (CTL) for 8 or 10 weeks. Saline (1.8%) and water intake were measured in metabolic cages. Urinary volume, osmolarity, Na+ and K+ concentrations, and plasma osmolarity were measured. The autonomic balance was estimated by heart rate variability at baseline or after icv injection of losartan. Cardiac function was assessed by echocardiography and ex vivo recordings. Myocardial collagen deposition was evaluated by Picrosirius-Red staining. Vascular reactivity and wall thickness were investigated in aortic sections. Blood pressure (BP) was assessed by tail-cuff plethysmography. Angiotensin II type I receptor (AT1R), renin, and mineralocorticoid receptor (MR) mRNA expression was measured in the kidneys and whole hypothalamus. AS group exhibited decreased urinary volume and Na+ concentration, while urinary K+ concentration, plasma osmolarity, and renal AT1R and renin mRNA levels were increased compared to CTL (p