ESTROGEN SUPPRESSES GASTRIC-MOTILITY RESPONSE TO THYROTROPIN-RELEASING-HORMONE AND STRESS IN AWAKE RATS

Symptoms associated with gastric motility alteration vary with stress and ovarian hormone status, most notably in women with irritable bowel syndrome. This study examines combined effects, comparing gastric mot ility during administration of a stress-related neuropeptide thyrotrop in-releasing hormone (TRH) and restraint stress in conscious rats of v aried ovarian hormone status. Adult rats were ovariectomized and impla nted with estrogen, progesterone, or vehicle-releasing pellets. After 21 days, intracerebroventricular (I.C.) cannula and gastric tension tr ansducer were implanted. After 25-27 days, motility was recorded durin g neuropeptide injection (TRH/saline I.C.) or restraint stress. TRH in duced increased motility in all groups; the response varied with hormo ne group, and was least and briefest in estrogen-treated rats. Motilit y during restraint varied with hormone group; it was diminished in est rogen-treated but not other groups. Ovarian hormone status (estrogen) modifies gut response to TRH and restraint stress. (C) 1998 John Wiley & Sons, Inc.