Exaggerated activity of HPA axis in obese rats fed normocaloric liquid nutrition.

Abstract

Experimental and clinical studies have shown alterations in activity of systems responsible for neuroendocrine stress response in obese individuals. Therefore we investigated the effect of palatable normocaloric liquid nutrition (Fresubin) on alterations in activity of the hypothalamic-pituitary-adrenal (HPA) axis in male Wistar rats of different developmental stages. Control rats (CON) received standard pellet chow all the time from weaning (21st day of age) to 150 days. Fresubin was administered throughout the experiment (LN), only in juvenility (from 21st to 90th day of age; LNJ) or only in adulthood (from 90th to 150th day of age; LNA). Body weight and energy intake were periodically monitored. Adrenal gland and fat tissue weight and plasma corticosterone levels (CORT) was determined after sacrification. Fresubin intake induced obesity in LN and LNA rats. In LN and LNA rats were observed elevated serum CORT levels, but only in LN rats with significant twofold increase compared to LNJ rats. However, the weight of adrenal glands did not differ between LN, LNJ and LNA experimental groups. Based on our results, we suggest, that obesity induced by Fresubin in LN and LNA rats is accompanied by increased HPA activity represented by elevated plasma CORT levels in these rats.