Abstract
Purpose : Regulation of food intake might be simply based on the total food energy ingested or could involve separate regulatory signals specific to each of the component nutrients. However, there are few data in regard to whether there is a regulation of the intake of individual macronutrients. Further, it is unclear whether food-deprivation can alter the levels of blood energy substrates in the weaning period. Therefore, the age-related effects of food-deprivation on plasma energy substrate (glucose, triglyceride and total cholesterol) levels in rats were studied. Methods : Infant (3 wks old), adult (7 wks old) and aged (50 wks old) Sprague Dawley male rats were divided into the control (CON) and the fasting (FAS) groups. Food-deprivations in the infant, adult and aged rats were maintained for 3, 6 and 8 days, respectively. Results : The body weights of FAS groups in three different aged rats decreased markedly with the increase of fasting days. Plasma glucose concentrations in FAS groups of three different aged rats were significantly lower than those in CON groups. Plasma triglyceride concentrations in FAS groups of infant and adult rats were significantly lower than those in CON groups. These results show that food-deprivation decreases age-dependently plasma glucose and triglyceride levels, and the magnitude of the decreased actions is in the order of infant>adult>aged rats. [Jpn J Physiol 54 Suppl:S233 (2004)]
