Otro
Food restriction promotes downregulation of myocardial L-type Ca2+ channels
Registro en:
Canadian Journal of Physiology and Pharmacology. Ottawa: Canadian Science Publishing, Nrc Research Press, v. 87, n. 6, p. 426-431, 2009.
0008-4212
10.1139/Y09-025
WOS:000267075200003
Autor
De Tomasi, Loreta Casquel
Bruno, Alessandro
Sugizaki, Mario Mateus
Lima-Leopoldo, Ana Paula
Nascimento, Andre Ferreira
de Oliveira Junior, Silvio Assis
Pinotti, Matheus Fecchio
Padovani, Carlos Roberto
Leopoldo, Andre Soares
Cicogna, Antonio Carlos
Resumen
Food restriction (FR) has been shown to impair myocardial performance. However, the mechanisms behind these changes in myocardial function due to FR remain unknown. Since myocardial L-type Ca2+ channels may contribute to the cardiac dysfunction, we examined the influence of FR on L-type Ca2+ channels. Male 60-day-old Wistar rats were fed a control or a restricted diet (daily intake reduced to 50% of the amount of food consumed by the control group) for 90 days. Myocardial performance was evaluated in isolated left ventricular papillary muscles. The function of myocardial L-type Ca2+ channels was determined by using a pharmacological Ca2+ channel blocker, and changes in the number of channels were evaluated by mRNA and protein expression. FR decreased final body weights, as well as weights of the left and right ventricles. The Ca2+ channel blocker diltiazem promoted a higher blockade on developed tension in FR groups than in controls. The protein content of L-type Ca2+ channels was significantly diminished in FR rats, whereas the mRNA expression was similar between groups. These results suggest that the myocardial dysfunction observed in previous studies with FR animals could be caused by downregulation of L-type Ca2+ channels.