Effect of the chronic stress in cardiovascular function in adolescents and adults rats

• Grant number: 12/01888-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2012
• End date: January 31, 2016
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Carlos Cesar Crestani
• Grantee: Josiane de Oliveira Duarte
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Studies in humans and animals have associated psychosocial factors, such as stress and psychiatric disorder, with cardiovascular diseases. Although the relevance of the topic, the mechanisms involved in cardiovascular pathologies associated with stress is still unknown. In animals, it has been used two models of psychological chronic stress: I) daily exposure to different stressors, and II) daily exposure to same stressor. Although some studies to suggest that these protocols of chronic stress may evoke different effects in behavior and neuroendocrine function, the effect of them in cardiovascular function has not been compared. The ontogeny is other factor that may affect the behavioral and physiological responses to stress. In this way, preclinical evidences suggest that adolescence is a period of enhanced vulnerability to negative consequences of the stress. However, a limited number of studies have investigated the effect of the stress in adolescents. Moreover, long-lasting consequences of exposure to stress during adolescence are not completely understood. The physiopathological mechanisms involved in cardiovascular complications associated with stress are still unknown. Studies have suggested that decreased baroreflex activity is an important mechanism involved in hypertension, and is a risk factor for the development of cardiac arrhythmia and sudden death in several cardiovascular diseases. However, evidences of the effect of chronic stress in baroreflex function are limited. Although some in vitro studies to report changes in vascular responses to vasoactive substances after exposure to chronic stress, there are no in vivo studies reporting effect of the exposure to chronic stress in vascular reactivity. An impaired vascular response is a precursor and a marker of atherosclerotic disease and changes in the action of vasodilator and vasoconstrictor agents has been proposed as a mechanism involved in development of hypertension. Finally, it has been reported rest tachycardia and increase in cardiac sympathetic activity in animals exposure to chronic variable stress. These changes in cardiac activity have been suggested as risk factors for development of cardiovascular diseases. Thus, the aims of the present study are: 1) to compare, in adult rats, the effect of the chronic variable stress and the repeated exposure to restraint stress in cardiovascular function; 2) to compare, in adolescents rats, the immediate and late effects (i.e., during adult phase) of the chronic variable stress and the repeated exposure to restraint stress in cardiovascular function; and 3) to study the effect of the chronic variable stress and the repeated exposure to restraint stress in cardiovascular function in adults animals that were exposure to chronic stress during adolescence. As functional measurements, we will analyze basal values of arterial pressure, heart rate and plasma corticosterone; baroreflex activity, vascular reactivity to vasoconstrictor and vasodilator agents; and cardiac autonomic balance. Moreover, we will analyze the weight of the heart, kidneys, adrenals and timo after the end of the experiments. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DUARTE, JOSIANE O.; GOMES, KARINA S.; NUNES-DE-SOUZA, RICARDO L.; CRESTANI, CARLOS C.. Role of the lateral preoptic area in cardiovascular and neuroendocrine responses to acute restraint stress in rats. Physiology & Behavior, v. 175, p. 16-21, JUN 1 2017. (12/14376-0, 15/05922-9, 12/01888-2)