Maternal Protein Restriction Increases Respiratory and Sympathetic Activities and Sensitizes Peripheral Chemoreflex in Male Rat Offspring

Autor(es):Mostrar menos -

de Brito Alves, Jose L. ^[1] ; Nogueira, Viviane O. ^[1] ; Cavalcanti Neto, Marinaldo P. ^{[2, 3]} ; Leopoldino, Andreia M. ^{[2, 3]} ; Curti, Carlos ^{[2, 3]} ; Colombari, Debora S. A. ^[4] ; Colombari, Eduardo ^[4] ; Wanderley, Almir G. ^[5] ; Leandro, Carol G. ^[1] ; Zoccal, Daniel B. ^[5] ; Costa-Silva, Joao H. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Pernambuco, Dept Phys Educ & Sport Sci, Vitoria De Santo Antao, PE - Brazil

^[2] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Phys & Chem, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Clin Anal Toxicol & Food Sci, Sao Paulo - Brazil

^[4] Sao Paulo State Univ, Sch Dent Araraquara, Dept Physiol & Pathol, Sao Paulo - Brazil

^[5] Univ Fed Pernambuco, Dept Physiol & Pharmacol, Recife, PE - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Nutrition; v. 145, n. 5, p. 907-914, MAY 2015.
• Citações Web of Science: 17

Resumo

Background: Maternal protein restriction in rats increases the risk of adult offspring arterial hypertension through unknown mechanisms. Objectives: The aims of the study were to evaluate the effects of a low-protein (LP) diet during pregnancy and lactation on baseline sympathetic and respiratory activities and peripheral chemoreflex sensitivity in the rat offspring. Methods: Wistar rat dams were fed a control {[}normal-protein (NP); 17% protein] or an LP (8% protein) diet during pregnancy and lactation, and their male offspring were studied at 30 d of age. Direct measurements of baseline arterial blood pressure (ABP), heart rate (HR), and respiratory frequency (Rf) as well as peripheral chemoreflex activation (potassium cyanide: 0.04%) were recorded in pups while they were awake. In addition, recordings of the phrenic nerve (PN) and thoracic sympathetic nerve (tSN) activities were obtained from the in situ preparations. Hypoxia-inducible factor l alpha (HIF-1 alpha) expression was also evaluated in carotid bifurcation through a Western blotting assay. Results: At 30 d of age, unanesthetized LP rats exhibited enhanced resting Rf (P = 0.001) and similar ABP and HR compared with the NP rats. Despite their similar baseline ABP values, LP rats exhibited augmented low-frequency variability (similar to 91%; P = 0.01). In addition, the unanesthetized LP rats showed enhanced pressor (P = 0.01) and tachypnoeic (P = 0.03) responses to peripheral chemoreflex activation. The LP rats displayed elevated baseline tSN activity (similar to 86%; P= 0.02) and PN burst frequency (45%; P= 0.01) and amplitude (53%; P= 0.001) as well as augmented sympathetic (P= 0.01) and phrenic (P= 0.04) excitatory responses to peripheral chemoreflex activation compared with the NP group. Furthermore, LP rats showed an increase of similar to 100% in HIF-1 alpha protein density in carotid bifurcation compared with NP rats. Conclusion: Sympathetic-respiratory overactivity and amplified peripheral chemoreceptor responses, potentially through HIF-1a dependent mechanisms, precede the onset of hypertension in juvenile rats exposed to protein undernutrition during gestation and lactation. (AU)

• Processo FAPESP: 09/54888-7 - Mecanismos neurais envolvidos na quimiorrecepção
• Beneficiário: Eduardo Colombari
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/20040-1 - Função colinérgica cardiorespiratória no núcleo do trato solitário
• Beneficiário: Débora Simões de Almeida Colombari
• Modalidade de apoio: Auxílio à Pesquisa - Regular