Cloning and Functional Characterization of an Avian Pituitary Gland Vasotocin Receptor

University Of Arkansas Medical Sciences Campus, Little Rock AR

Investigators

Abstract

The hypothalamo-pituitary-adrenal axis in vertebrate animals is important for regulation of responses to stress, chiefly by release of adrenocorticotropic hormone (ACTH) from the pituitary, which in turn stimulates release of steroid glucocorticoids from the adrenal glands. In birds, the peptide compound arginine vasotocin (AVT), which regulates water balance and reproduction, may be a major factor regulating ACTH release from the pituitary gland, though this function has not yet been well defined in birds. This project tests the hypothesis that a novel VT receptor molecule is expressed by certain cells in the pituitary, and mediates the stimulatory effect of AVT on ACTH release. A collaborative team with complementary skills will use molecular, cellular, biochemical and behavioral approaches in a uniquely integrative, comparative study to clone and characterize this novel receptor, to localize the cells expressing the receptors, and to establish the physiological role for the VT receptors. Results will be important in neuroendocrinology for understanding comparative aspects of pituitary function in vertebrates other than mammals; for an integrated understanding of molecular, cellular and behavioral mechanisms for stress regulation; and for general aspects of poultry reproduction. It will also have a broader impact on bird physiology, on general vertebrate endocrinology and reproductive behavior. There is also a strong impact on scientific infrastructure because the project has a training component including graduates and undergraduates, and involves three campuses in an EPSCoR state.