EFFECTS OF CHRONIC ADMINISTRATION OF NANDROLONE DECANOATE ON CORONARY BED REACTIVITY AND CARDIAC CONTRATILITY IN WISTAR RATS SUBMITTED TO RESISTANCE PHYSICAL TRAINING.

• Grant number: 22/08846-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2023
• End date: January 31, 2025
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Hugo Celso Dutra de Souza
• Grantee: Lucas Dalvit Ferreira
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Introduction: Androgenic anabolic steroids (AAS) are natural or synthetic compounds, formed from testosterone and its derivatives, which are widely used in clinical practice for the treatment of various diseases, mainly related to androgenic dysfunctions. However, due to their anabolic potential, these substances are often used without therapeutic prescription in sports, with the aim of enhancing physical abilities. In this case, some studies that addressed the effects of AAS on physiological systems suggested that the indiscriminate and unsupervised use of AAS, in addition to other effects, may promote cardiovascular damage, characterized by concentric cardiac hypertrophy, alterations in the regulation of coronary flow and hypertension arterial. However, despite the importance of these observations, many of the findings are controversial, in addition to being incipient, in relation to cardiac contractility and coronary bed reactivity, mainly with regard to the effects of the association with resistance physical training. Our hypothesis is that this association may cause significant damage to cardiac contractility and coronary flow reactivity, which would result in reduced cardiac cardiofunctional capacity. Objective: To investigate, in experimental animals, the effects of treatment with nandrolone decanoate, a well-known AAS, associated with resistance training, on hemodynamic parameters, morphology and cardiac functionality, focusing on coronary bed reactivity and left ventricular contractility. Methods: Adult male Wistar rats (N=64), 16 weeks old (350-380g), will be divided into four groups (N=16); vehicle-treated control group (Vehicle Group); group treated with nandrolone decanoate (5mg/kg) for 12 weeks (Nandrolone Group); vehicle-treated group submitted to resisted physical training for 12 weeks (Trained Vehicle Group); and the group treated with nandrolone decanoate (5mg/kg) and submitted to resistance training for 12 weeks (Nandrolone Trained Group). All groups will undergo the following experimental procedures; recording of blood pressure and heart rate using plethysmography to be performed at the 18th, 22nd, 26th and 30th weeks of life; cardiac morphofunctional assessment through two-dimensional echocardiography at the 18th and 30th weeks; analysis of coronary bed reactivity and left ventricular contractility in an isolated heart (Lagendorff technique) by means of increased flow and administration of ²-adrenergic agonists, dobutamine and salbutamol; quantification of expression of cardiac ²-adrenergic receptors; and cardiac histological analysis.