Malnutrition enhances cardiovascular responses to chemoreflex activation in awake rats

• Published in: Life sciences (1973) 2007-07, Vol.81 (7), p.609-614
• Main Authors: Penitente, Arlete Rita, Fernandes, Luciano Gonçalves, Cardoso, Leonardo Máximo, Silva, Marcelo Eustáquio, Pedrosa, Maria Lúcia, Silva, Antônio Leite, Haibara, Andréa Siqueira, Moraes, Márcio Flávio Dutra, Chianca, Deoclécio Alves
• Format: Article
• Language: English
• Subjects: Albumin; Animals; Arterial pressure; Autonomic Nervous System - physiology; Blood Glucose - metabolism; Blood Pressure - physiology; Blood Proteins - metabolism; Cardiovascular Physiological Phenomena; Carotid Arteries - physiology; Carotid Body - physiology; Chemoreflex; Diet; Heart Rate - drug effects; Low-protein diet; Male; Malnutrition - blood; Malnutrition - physiopathology; Potassium Cyanide - pharmacology; Rats; Rats, Inbred F344; Reflex - drug effects; Reflex - physiology; Serum Albumin - metabolism; Sympathetic activity
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2007.07.006

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.