Swimming exercise changes hemodynamic responses evoked by blockade of excitatory amino receptors in the rostral ventrolateral medulla in spontaneously hypertensive rats.
Exercise training reduces sympathetic activity in hypertensive humans and rats. We hypothesized that the swimming exercise would change the neurotransmission in the rostral ventrolateral medulla (RVLM), a key region involved in sympathetic outflow, and hemodynamic control in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. Bilateral injections of kynurenic acid (KYN) were carried out in the RVLM in sedentary- (S-) or exercised- (E-) SHR and WKY rats submitted to swimming for 6 weeks. Rats were α-chloralose anesthetized and artificially ventilated, with Doppler flow probes around the lower abdominal aorta and superior mesenteric artery. Injections into the RVLM were made before and after i.v. L-NAME (nitric oxide synthase, NOS, inhibitor). Injections of KYN into the RVLM elicited a major vasodilation in the hindlimb more than in the mesenteric artery in E-SHR compared to S-SHR, but similar decrease in arterial pressure was observed in both groups. Injections of KYN into the RVLM after i.v. L-NAME attenuated the hindlimb vasodilation evoked by KYN and increased the mesenteric vasodilation in E-SHR. Swimming exercise can enhance the hindlimb vasodilation mediated by peripheral NO release, reducing the activation of neurons with EAA receptors in the RVLM in SHR.
Department of Physiology, Faculdade de Medicina do ABC (FMABC), Avenida Principe de Gales 821, Vila Principe de Gales, 09060-650 Santo Andre, SP, Brazil ; Department of Physiology, Federal University of Sao Paulo (UNIFESP), Rua Botucatu 862, Vila Clementino, 04023-901 Sao Paulo, SP, Brazil.
Cristiana A
CA
Ogihara
Department of Physiology, Federal University of Sao Paulo (UNIFESP), Rua Botucatu 862, Vila Clementino, 04023-901 Sao Paulo, SP, Brazil.
Gerhardus H M
GH
Schoorlemmer
Department of Pharmacology, Federal University of Sao Paulo (UNIFESP), Rua Tres de Maio 100, Vila Clementino, 04044-020 Sao Paulo, SP, Brazil.
Maria de Fátima M
Mde F
Lazari
Department of Physiology, Faculdade de Medicina do ABC (FMABC), Avenida Principe de Gales 821, Vila Principe de Gales, 09060-650 Santo Andre, SP, Brazil.
Gisele
0000-0002-0126-7677
G
Giannocco
Department of Physiology, Federal University of Sao Paulo (UNIFESP), Rua Botucatu 862, Vila Clementino, 04023-901 Sao Paulo, SP, Brazil.
Oswaldo U
OU
Lopes
Department of Pathology and Physiology, School of Dentistry, Sao Paulo State University (UNESP), Rua Humaita 1680, Centro, 14801-385 Araraquara, SP, Brazil.
Eduardo
E
Colombari
Department of Physiology, Faculdade de Medicina do ABC (FMABC), Avenida Principe de Gales 821, Vila Principe de Gales, 09060-650 Santo Andre, SP, Brazil.
Monica A
MA
Sato
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects; D018698:Glutamic Acid / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007736:Kynurenic Acid / Q000494:pharmacology; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D010805:Physical Conditioning, Animal; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017470:Receptors, Glutamate / Q000378:metabolism*; D013550:Swimming
D017470:Receptors, Glutamate; D009569:Nitric Oxide; D018698:Glutamic Acid; D007736:Kynurenic Acid