Effects of Starvation on Levels of Corticotrophin Releasing Factor, Corticotrophin and Plasma Corticosterone in Rats

Abstract

Rats were starved for seven days and the effects on corticotrophin releasing factor (CRF) content in the stalk median eminence (SME), corticotrophin content in the anterior pituitary gland (AP), basal plasma corticosterone response to ethyl ether stress were determined. The weight changes in the adrenal and anterior pituitary glands were also studied. When compared to the control group, starvation resulted in a significant increase in stored GRF in the SME. There was a decrease in the corticotrophin content in the AP during starvation but the differences between the starved and the control group were not statistically significant. Pre-and post-stress plasma levels of corticosterone were significantly increased in the starved animals. The weights of the adrenals and of the anterior pituitary glands were significantly increased in the starved animals, when calculated per 100 g body weight. The absolute weight of the adrenals was not significantly increased in the starved animals. There was a significant decrease in the absolute weight of the AP.Changes in the content of the various neurohormones in the hypothalamus have been observed under various physiological conditions. The level of the stored LH-releasing factor changes with the oestrous cycle (Ramirez Se Sawyer 1965; Chowers Sc McCann 1965), and starvation causes a decrease in the rate of

Prolonged Food Deprivation Abolishes the Circadian Adrenocortical Rhythm, but Not the Endogenous Rhythm in Rats

“…Chowers et al [2] also re ported a remarkable increase in corticosterone levels in plasma after 7 days of food depriva tion. In our study, an increment in blood corticosterone levels by food deprivation was not observed.…”

Adrenocortical Function in the Horse

“…Acetyl promazine,thiopentone and halothanedid not themselves elicit an increase. The adrenocortical response to anaesthesia depends upon the nature of the anaesthetic ; many authors have shown that ether anaesthesia produces a response in man and other animals (Virtue, Helmreich & Gainza, 1957;Chowers, Einat & Feldman, 1969;Oyama, Shibata, Matsuki & Kudo, 1969) as does Nembutal (Moncloa, Péron & Dorfman, 1959;Nagle, Cammock, Nyhus & Harkins, 1965), whereas thiopentone and halothane produce no change in man (Oyama, Shibata, Matusmoto, Takiguchi & Kudo, 1968).…”

Opposing Crosstalk between Leptin and Glucocorticoids Rapidly Modulates Synaptic Excitation via Endocannabinoid Release

“…The HPA axis controls circulating levels of GCs, which are the main endocrine signal in the adaptation to stress and are also a major signal for the maintenance of energy homeostasis via control of metabolism and appetite (Castonguay, 1991;Sapolsky et al, 2000). Fasting is a metabolic stress that increases the circulating levels of GCs and decreases the circulating levels of leptin (Chowers et al, 1969;Ahima, 2000), the primary endocrine signal of the nutritional state. This hormonal profile sets the stage for vital behavioral and physiological adaptations that take place during caloric deficit to promote the reestablishment of energy balance.…”