Malnutrition enhances cardiovascular responses to chemoreflex activation in awake rats.
Several studies in the literature suggest that low-protein intake is associated with increases in sympathetic efferent activity and cardiovascular disease. Among the possible mechanisms, changes in the neurotransmission of cardiovascular reflexes have been implicated. Therefore, the present study comprised the evaluation of chemoreflex responsiveness in rats subjected to a low-protein diet during the 35 days after weaning. As a result, we observed that malnourished rats presented higher levels of baseline mean arterial pressure and heart rate and exhibited a mild increase in the pressor response to chemoreflex activation. They also exhibited a massive bradycardic response to chemoreflex activation. Interestingly, bilateral ligature of the carotid body arteries further increased baseline mean arterial pressure and heart rate in malnourished animals. The data suggest severe autonomic imbalance and/or change in the central interplay between neural and cardiovascular mechanisms.
Penitente
Arlete Rita
AR
Department of Biological Sciences, ICEB/NUPEB, Federal University of Ouro Preto, 35400-000, Ouro Preto, MG, Brazil.
Fernandes
Luciano Gonçalves
LG
Cardoso
Leonardo Máximo
LM
Silva
Marcelo Eustáquio
ME
Pedrosa
Maria Lúcia
ML
Silva
Antônio Leite
AL
Haibara
Andréa Siqueira
AS
Moraes
Márcio Flávio Dutra
MF
Chianca
Deoclécio Alves Júnior
DA
D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D001798:Blood Proteins / Q000378:metabolism; D002320:Cardiovascular Physiological Phenomena; D002339:Carotid Arteries / Q000502:physiology; D002344:Carotid Body / Q000502:physiology; D004032:Diet; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D044342:Malnutrition / Q000097:blood / Q000503:physiopathology*; D011190:Potassium Cyanide / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D012018:Reflex / Q000187:drug effects / Q000502:physiology*; D012709:Serum Albumin / Q000378:metabolism
D001786:Blood Glucose; D001798:Blood Proteins; D012709:Serum Albumin; D011190:Potassium Cyanide