Effects of chronic anabolic steroid treatment on tonic and reflex cardiovascular control in male rats.
The aim of this study was to analyze the cardiovascular effects of chronic stanozolol administration in male rats. The rats were randomly assigned to one of three groups: (1) control (n=12), (2) chronic treatment with low dose of stanozolol (LD, n=18, 5 mg/kgweek) and; (3) treatment with high dose of stanozolol (HD, n=28, 20 mg/kgweek). Mean arterial pressure (MAP) was higher in both HD (128+/-2.2 mmHg) and LD (126+/-2.5 mmHg) than control (116+/-2 mmHg). The LD group showed an increase in cardiac output (control 121+/-2.5, LD 154+/-5.9 ml/min), whereas in the HD group total peripheral resistance increased (control 1.03+/-0.07, HD 1.26+/-0.07 mmHg/ml/min). Acute sympathetic blockade caused a similar decrease in MAP in all groups. In conscious rats, the baroreflex index for bradycardia (control -3.7+/-0.4, LD -2.0+/-0.1 beat/mmHg) and tachycardia (control -3.6+/-0.3, LD -4.7+/-0.2 beat/mmHg) responses changed only in the LD group. Cardiac hypertrophy was observed in both treated groups (P<0.05). In conclusion, hypertension with differential hemodynamic changes and alterations in the reflex control in heart rate is seen at different stanozolol doses, which may be important variables in the cardiovascular effects of anabolic steroids.
Beutel
Abram
A
Department of Physiology, Federal University of São Paulo, Paulista School of Medicine, São Paulo, SP, Brazil.
Bergamaschi
Cássia Toledo
CT
Campos
Ruy Ribeiro
RR
D045930:Anabolic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D017704:Baroreflex / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D001919:Bradycardia; D002302:Cardiac Output / Q000187:drug effects; D006332:Cardiomegaly / Q000139:chemically induced; D002316:Cardiotonic Agents / Q000494:pharmacology; D002319:Cardiovascular System / Q000187:drug effects*; D003243:Consciousness; D004334:Drug Administration Schedule; D005730:Ganglionic Blockers / Q000494:pharmacology; D018738:Hexamethonium / Q000494:pharmacology; D007279:Injections, Subcutaneous; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013197:Stanozolol / Q000008:administration & dosage / Q000494:pharmacology*; D013564:Sympathetic Nervous System / Q000187:drug effects*; D013610:Tachycardia; D013739:Testosterone / Q000097:blood; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D045930:Anabolic Agents; D002316:Cardiotonic Agents; D005730:Ganglionic Blockers; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D018738:Hexamethonium; D013739:Testosterone; D013197:Stanozolol