Effects of pregnancy in rats on cysteamine-induced peptic ulcers: role of progesterone.
After mating with a sexually active male, groups of female Sprague-Dawley rats were injected with cysteamine (400 mg/kg, subcutaneously) at day 0 (controls), day 5 (early-stage pregnancy), and day 18 (late-stage pregnancy) of pregnancy. In contrast to late-stage pregnancy rats, early-stage pregnancy animals showed a decrease of cysteamine-induced gastroduodenal lesions. When subjected to cysteamine injection, both nonpregnant female and male rats treated for eight days with progesterone (300 microg/rat, subcutaneously) showed a reduced incidence of gastroduodenal lesions. No effect was found in animals pretreated with 17beta-estradiol (200 microg/rat, subcutaneously). Furthermore, increased gastroduodenal mucus levels were found in early-stage pregnancy rats and in animals pretreated with progesterone. These results suggest that increased progesterone plasma levels during early-stage pregnancy may be involved in pregnancy-induced gastric and duodenal protection. This effect may be related to an increase in gastric and duodenal mucus production induced by this hormone.
Montoneri
C
C
Institute of Pharmacology, University of Catania Medical School, Italy.
Drago
F
F
D000818:Animals; D003543:Cysteamine; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D008297:Male; D009093:Mucus / Q000502:physiology; D010437:Peptic Ulcer / Q000139:chemically induced* / Q000517:prevention & control; D011247:Pregnancy; D011248:Pregnancy Complications / Q000139:chemically induced*; D011374:Progesterone / Q000494:pharmacology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D011374:Progesterone; D004958:Estradiol; D003543:Cysteamine