motilin and Haemonchiasis

Plasma levels of pancreatic polypeptide (PP), somatostatin (GH-RIH), gastrin and motilin were measured during 6-7 h after oral infection with 25 000 infective (3rd stage) larvae of H. contortus in lambs or after intravenous injection of larvae or worm antigenic (Ag) extracts. A 3-fold increase in plasma gastrin was observed during the first 60 min after infection and GH-RIH increased significantly (P less than 0.01) 180 min later whereas both PP and motilin remained unchanged. An early (60 to 120 min) increase in GH-RIH and a late (5 to 7 h) increase in PP plasma levels were observed after both worm and larvae antigenic extracts whereas plasma motilin was unaffected. Plasma gastrin was significantly (P less than 0.01) increased during 3-4 h following the injection of worm but not of larvae antigenic extract. It was concluded that the immediate hypergastrinemia following H. contortus infection is not the consequence of a general immune response of the host and is probably related to the release of unknown substance(s) by the infective larvae into the abomasum or to mucosal inflammation due to a local immune response; in contrast, the increase in plasma GH-RIH levels appeared to be the result of antigenic reactions. The other hormonal changes observed after Ag injections may be the consequence rather than the reason of changes in abomasal secretory pattern.

Topics: Animals; Gastrointestinal Hormones; Haemonchiasis; Intestinal Diseases, Parasitic; Motilin; Pancreatic Polypeptide; Sheep; Sheep Diseases; Somatostatin; Trichostrongyloidiasis