hormone secreted in the intestines to regulate the body’s salt/water balance, induce relaxation of digestive muscles, and aid absorption of glucose and lipids; small amount secreted by the anterior lobe of the pituitary gland to stimulate nest-building and growth of ovarian follicles; secreted also by the hypothalamus to stimulate secretion of prolactin to encourage growth of mature ovarian follicles prior to ovulation; secreted by the adrenal medulla to induce release of other adrenal hormones in response to stress; stimulates metabolism and growth in young birds; abbreviated VIP