gastrins and Trichinellosis

This study tested the hypothesis that the inhibitory action of secretin on gastrin-stimulated gastric acid and pepsin secretion is comprised in animals harboring intestinal stages of the parasite Trichinella spiralis. Pentagastrin-stimulated acid and pepsin secretion, and the influence of secretin on these processes, were measured in dogs prepared with gastric fistulas and Heidenhain pouches. Dogs were studied before and after infection with 10(4) T. spiralis larvae/kg body weight. Gastric secretion was stimulated by constant intravenous infusion of pentagastrin, 1 microgram/kg per hour. Exogenous secretin inhibited pentagastrin-stimulated acid and pepsin output from both the main stomach and Heidenhain pouch in infected as well as in the uninfected dogs. Identical inhibition was observed in uninfected dogs during duodenal infusion with HCl to release endogenous secretin. In contrast, duodenal stimulation with HCl did not inhibit acid and pepsin secretion in dogs tested during the 1st week following infection. Results support the conclusion that the regulatory effect of secretin on gastrin-stimulated gastric secretion is impaired during the early phase of infection, and is due to depressed synthesis or release of secretin from duodenal mucosa.

Topics: Animals; Dogs; Gastric Juice; Gastrins; Pentagastrin; Secretin; Trichinellosis

Serum and antral gastrin were measured in rats infected with either Trichinella spiralis or Hymenolepis diminuta as a step in testing the hypothesis that parasites change certain aspects of host physiology by altering gastrointestinal (GI) hormone levels or responses to GI hormones. Parasitism with T. spiralis was associated with inflammatory changes in the small bowel mucosa and with a significant increase in serum gastrin. Neither changes in hormone level nor inflammation were induced in tapeworm-infected rats. These results reveal the capacity of tissue penetrating parasites to alter the level of circulating gastrin. This finding coupled with considerable indirect evidence suggests that some of the pathologic changes induced in hosts by enteric parasites may be due to changes in functions that are regulated by GI hormones.

Topics: Animals; Body Weight; Gastrins; Hymenolepiasis; Intestinal Diseases, Parasitic; Male; Pyloric Antrum; Rats; Trichinellosis