AJP - Regulatory, Integrative and Comparative Physiology, Vol 266, Issue 5 1448-R1453, Copyright © 1994 by American Physiological Society
Role of endogenous vasopressin in development of gastric ulcer induced by restraint and water immersion
K. Honda, S. Fukuda, S. E. Ishikawa, T. Kuzuya and T. Saito
Department of Medicine, Jichi Medical School, Tochigi, Japan.
To elucidate the role of arginine vasopressin (AVP) in the development of
stress-induced gastric ulcer, the mucosal lesions after restraint and water
immersion were examined in Brattleboro strain rats with hereditary
hypothalamic diabetes insipidus (DI) and in Long-Evans rats (LE) used as
controls. Restrained animals were immersed in water for 2 h, and the size
of lesion was expressed as percentage of the lesion area to the total
glandular mucosal area, which were defined as ulcer index (UI). In DI rats,
UI was significantly higher than in control LE rats, despite the attenuated
responses of plasma adrenocorticotropic hormone (ACTH) to stress. Although
subcutaneous injection of selective antidiuretic analogue
1-desamino-8-D-AVP did not affect UI, intracerebroventricular (icv)
administration of AVP reduced UI in DI rats, and icv administration of V1
antagonist [d(CH2)5Tyr(Me)]AVP elevated UI in LE rats. These results
indicate that endogenous AVP plays a role in preventing the formation of
gastric ulcers induced by stress via a central V1 receptor. Furthermore, we
suggest that elevation of ACTH in plasma is not essential in the
development of stress-induced gastric ulcer in rats.
