Effect of short-term fasting on the expression of ACTH (cMC2) receptor in the adrenal glands of chickens (Gallus gallus domesticus)

The main hormone produced by the adrenal glands of hens is corticosterone, synthesized and secreted by stimulation of the HPA axis during stress. Direct activation of adrenal activity is conditioned by ACTH, which binds to the melanocortin receptor cMC2 in the adrenals and stimulates the synthesis and release of glucocorticosteroids. One of the factors that stimulate HPA axis activity is starvation, to which chickens are very sensitive. The purpose of this study was to determine the expression of ACTH receptor cMC2 in the adrenals of hens during short- term fasting and after restoration of the proper level of nutrition (refeeding). The results of the experiment show that 24-hour food deprivation is stressful for the hen, as indicated by increased concentrations of corticosterone in the adrenals and blood plasma. Changes in cMC2R expression and the level of corticosterone in the adrenals during fasting and refeeding indicate a rapid increase in HPA axis activity in response to changing levels of nutrition. The results of the experiment confirm the direct effect of ACTH on corticosterone release by avian adrenal glands.