RESUMO
Anabolic Androgenic Steroids (AASs) misuse has increased among adolescents and recreational athletes due to their potential effects on muscle hypertrophy. On the other hand, AAS might induce alterations on cardiovascular system, although some controversies regarding AAS on vascular properties remain unknown. To address this question, we aimed to investigate the effects of high doses of nandrolone combined with strenuous resistance training (RT) on function and structure of thoracic aorta. Rats were randomized into four groups: non-trained vehicle (NTV), trained vehicle (TV), non-trained nandrolone (NTN), and trained nandrolone (TN), and submitted to 6â¯weeks of treatment with nandrolone (5â¯mg/kg, twice a week) and/or resistance training. In vitro response of thoracic aorta to acetylcholine (ACh) was analyzed. Vascular nitric oxide (NO) and reactive oxygen species (ROS) synthesis were evaluated using 4,5-diaminofluorescein diacetate (DAF-2) and hydroethidine fluorescent techniques, respectively. Thoracic aorta was processed for microscopy analyses and tunica media thickness was measured. ACh-mediated relaxation response was impaired in endothelium intact aortic rings isolated from trained rats (TV and TN) as compared with their matched non-trained groups. TN rats showed reduced ACh-mediated vasodilatation than NTN rats. NO production and bioavailability decreased in thoracic aorta of nandrolone-treated rats in relation to their matched non-trained group (NTN vs. NTV; TN vs. TV). ROS production and tunica media thickness were increased in TN rats when compared with TV rats. These findings indicate that high doses of nandrolone combined with strenuous RT affect NO bioavailability and might induce endothelial dysfunction and arterial morphological alterations.
Assuntos
Aorta Torácica/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Nandrolona/farmacologia , Óxido Nítrico/metabolismo , Treinamento Resistido , Vasodilatação/efeitos dos fármacos , Animais , Aorta Torácica/metabolismo , Aorta Torácica/fisiologia , Disponibilidade Biológica , Endotélio Vascular/metabolismo , Masculino , Ratos , Ratos WistarRESUMO
AIMS: This study was performed to assess isolated and combined effects of nandrolone and resistance training on the blood pressure, cardiac electrophysiology, and expression of the ß1- and ß2-adrenergic receptors in the heart of rats. MAIN METHODS: Wistar rats were randomly divided into four groups and submitted to a 6-week treatment with nandrolone and/or resistance training. Cardiac hypertrophy was accessed by the ratio of heart weight to the final body weight. Blood pressure was determined by a computerized tail-cuff system. Electrocardiography analyses were performed. Western blotting was used to access the protein levels of the ß1- and ß2-adrenergic receptors in the right atrium and left ventricle. KEY FINDINGS: Both resistance training and nandrolone induced cardiac hypertrophy. Nandrolone increased systolic blood pressure depending on the treatment time. Resistance training decreased systolic, diastolic and mean arterial blood pressure, as well as induced resting bradycardia. Nandrolone prolonged the QTc interval for both trained and non-trained groups when they were compared to their respective vehicle-treated one. Nandrolone increased the expression of ß1- and ß2-adrenergic receptors in the right atrium for both trained and non-trained groups when they were compared to their respective vehicle-treated one. SIGNIFICANCE: This study indicated that nandrolone, associated or not with resistance training increases blood pressure depending on the treatment time, induces prolongation of the QTc interval, and increases the expression of ß1- and ß2-adrenergic receptors in the cardiac right atrium, but not in the left ventricle.
Assuntos
Anabolizantes/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Coração/efeitos dos fármacos , Miocárdio/metabolismo , Nandrolona/farmacologia , Condicionamento Físico Animal , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Animais , Western Blotting , Peso Corporal , Cardiomegalia , Eletrocardiografia , Coração/fisiologia , Frequência Cardíaca , Masculino , Ratos , Ratos WistarRESUMO
AIMS: This study was conducted to assess the isolated and combined effects of nandrolone and resistance training on cardiac morphology, function, and mRNA expression of pathological cardiac hypertrophy markers. MAIN METHODS: Wistar rats were randomly divided into four groups and submitted to 6 weeks of treatment with nandrolone and/or resistance training. Cardiac parameters were determined by echocardiography. Heart was analyzed for collagen infiltration. Real-time RT-PCR was used to assess the pathological cardiac hypertrophy markers. KEY FINDINGS: Both resistance training and nandrolone induced cardiac hypertrophy. Nandrolone increased the cardiac collagen content, and reduced the cardiac index in non-trained and trained groups, when compared with the respective vehicle-treated groups. Nandrolone reduced the ratio of maximum early to late transmitral flow velocity in non-trained and trained groups, when compared with the respective vehicle-treated groups. Nandrolone reduced the alpha-myosin heavy chain gene expression in both non-trained and trained groups, when compared with the respective vehicle-treated groups. Training reduced the beta-myosin heavy chain gene expression in the groups treated with vehicle and nandrolone. Only the association between training and nandrolone increased the expression of the skeletal alpha-actin gene and atrial natriuretic peptide in the left ventricle. SIGNIFICANCE: This study indicated that nandrolone, whether associated with resistance training or not, induces cardiac hypertrophy, which is associated with enhanced collagen content, re-expression of fetal genes the in left ventricle, and impaired diastolic and systolic function.