Sistema colinérgico central modula os ajustes dos sistemas cardiovascular e termorregulatório induzidos pelo exercício físico até a fadiga

• Ano de defesa: 2007
• Autor(a) principal: Roberta Borges La Guardia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Educação Física; Pressão arterial Medição; Corpo Temperatura Regulação; Fisostigmina; Fadiga; Processos Fisiológicos Cardiovasculares; Exercícios físicos Aspectos fisiológicos; Receptores colinérgicos
• Link de acesso: http://hdl.handle.net/1843/KMCG-7GKQ68

ABSTRACTThe purpose of this study was to verify if the cardiovascular andthermoregulatory adjustments mediated by central cholinergic receptors andperipheral cathecolamines during the physical exercise until fatigue. Wistar ratsweighting 278 ± 5 g, were submitted to bilateral adrenodemedullation (ADM) or sham(SHAM) surgery. After recovery, the animals were subjected to 3 additional surgeries:implantations of intracerebroventricular guide cannulae; of aortic catheter into leftcarotid and intraperitoneal implantation of thermal sensor. The animals were dividedinto 4 groups: SHAM or ADM groups submitted to exercise at 24 m/min and 5%inclination (~80% of VO2max) until fatigue, SHAM or ADM groups with no exercise.Each group received 2 experimental treatments: icv injection of 2 µL of 5 x 10-3 Mphysostigmine (FIS) or 0,15 M NaCl (SAL). Environmental temperature was 24,7 ±0,1ºC. No difference was found between groups or treatments in time to fatigue. InADM group the FIS increased exercise mean blood pressure (ADM-EX-SAL 16 ±4mmHg vs ADM-EX-FIS 33 ± 3mmHg, p<0,05). The intraperitoneal temperatureincreased in the ADM-EX group, but wasn´t different between the treatments (ADMEX-SAL 0,5 ± 0,1°C vs ADM-EX-FIS 0,5 ± 0,1°C). The tail temperature increased inthe ADM-EX-FIS group (ADM-EX-SAL 2,9 ± 0,6°C vs ADM-EX-FIS 4,1 ± 0,°C,p<0,05). No difference was found between ADM and SHAM. Heat loss andcardiovascular adjustments modulated by the central cholinergic receptors duringexercise are independ from the action of peripheral cathecolamines.