Regulation of stress responses by peptides and small nitrogenous compounds in neonatal chicks

Understanding the regulation of stress responses in animals is very important. Stress influences the productivity of domestic animals. One of the routes for activation of the stress response is dependent on corticotropin-releasing factor (CRF), which regulates the secretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary. In neonatal chicks, CRF acts within the central nervous system to decrease food intake and increase locomotion. Within the CRF family, the order of the suppressive effect on food intake was CRF, urotensin I, and urocortin, which is different from results in mammals. α-Melanocortin stimulating hormone (α-MSH), as well as ACTH, are proopiomelanocortin-derived peptides. The intracerebroventricular injection of α-MSH strongly inhibits food intake, and interacts with neuropeptide Y, a major orexigenic factor of chicks, in the brain to control food intake. Stressful behaviour in chicks is attenuated by neuropeptides such as glucagon-like peptide-1 or by small nitrogenous compounds such as glutathione and creatine, but the reverse was true for carnosine and anserine. It is suggested that regulation of stress is somewhat specific, and multiple regulators control the stress response in newly hatched chicks.