1. Repositório Institucional da UFMG
2. Publicações Científicas e Culturais
3. Artigo de Periódico

Type:	Artigo de Periódico
Title:	Rats with higher intrinsic exercise capacities exhibit greater preoptic dopamine levels and greater mechanical and thermoregulatory efficiencies while running
Authors:	Patrícia da Conceição Rocha Rabelo Letícia Maria de Souza Cordeiro Nayara Soares Sena Aquino Bruno Bernardo Barbosa Fonseca Cândido Celso Coimbra Samuel Penna Wanner Raphael Escorsim Szawka Danusa Dias Soares
Abstract:	The present study investigated whether intrinsic exercise capacity affects the changes in thermoregulation, metabolism and central dopamine (DA) induced by treadmill running. Male Wistar rats were subjected to three incremental exercises and ranked as low-performance (LP), standard-performance (SP), and high-performance (HP) rats. In the first experiment, abdominal (TABD) and tail (TTAIL) temperatures were registered in these rats during submaximal exercise (SE) at 60% of maximal speed. Immediately after SE, rats were decapitated and concentrations of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) were determined in the preoptic area (POA). In the second experiment, oxygen consumption was measured and mechanical efficiency (ME) was calculated in these rats during an incremental exercise. HP rats ran for longer periods and were fatigued with higher TABD values, with no difference in TTAIL. Nevertheless, thermoregulatory efficiency was higher in HP rats, compared with other groups. DA and DOPAC concentrations in the POA were increased by SE, with higher levels in HP compared with LP and SP rats. V̇o2 also differed between groups, with HP rats displaying a lower consumption throughout the incremental exercise but a higher V̇o2 at fatigue. ME, in turn, was consistently higher in HP than in LP and SP rats. Thus, our results show that HP rats have greater TABD values at fatigue, which seem to be related to a higher dopaminergic activity in the POA. Moreover, HP rats exhibited a greater thermoregulatory efficiency during exercise, which can be attributed to a lower V̇o2, but not to changes in tail heat loss mechanisms. NEW & NOTEWORTHY: Our findings reveal that rats with higher intrinsic exercise capacities have greater thermoregulatory efficiencies and increased dopaminergic activity in the preoptic area, a key brain area in thermoregulatory control, while exercising. Moreover, higher intrinsic exercise capacities are associated with decreased oxygen consumption for a given exercise intensity, which indicates greater mechanical efficiencies. Collectively, these findings help to advance our knowledge of why some rats of a given strain can exercise for longer periods than others.
Subject:	Fadiga Aminas Consumo de oxigênio Desempenho Temperatura
language:	eng
metadata.dc.publisher.country:	Brasil
Publisher:	Universidade Federal de Minas Gerais
Publisher Initials:	UFMG
metadata.dc.publisher.department:	EEF - DEPARTAMENTO DE EDUCAÇÃO FÍSICA ICB - DEPARTAMENTO DE FISIOLOGIA E BIOFÍSICA
Rights:	Acesso Aberto
metadata.dc.identifier.doi:	https://doi.org/10.1152/japplphysiol.00092.2018
URI:	http://hdl.handle.net/1843/43829
Issue Date:	2019
metadata.dc.url.externa:	https://journals.physiology.org/doi/full/10.1152/japplphysiol.00092.2018?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org
metadata.dc.relation.ispartof:	Journal of Applied Physiology
Appears in Collections:	Artigo de Periódico

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.