Inhibition of hydrochloric acid and pepsin secretion from gastric pouches by antral pouch acidification in sheep.

Abstract

SUMMARY1. Secretion of acid and pepsin from separated pouches of the body of the abomasum was studied in sheep during perfusion of antral pouches with acid solutions.2. Resting secretion of acid and pepsin was reduced by acidification of antral pouches to pH 2-7 or less.3. Increases in the secretion of HCl and pepsin normally obtained on feeding were reduced or abolished by perfusion of antral pouches with solutions at pH 1-3-2*0.4. Perfusion of antral pouches with acetylcholine at pH 2-5 failed to stimulate acid secretion as it did at a higher pH.5. Pentagastrin stimulated acid and pepsin secretion during the inhibition of secretion produced by antral pouch acidification.6. Increases in reticular motility occurred on antral pouch acidification with solutions of pH 1 1-1 3.7. The contribution of antral pH in regulating abomasal acid secretion is discussed.

Effects of Ostertagia circumcincta infections on plasma gastrin in sheep

“…It is not known how the hypergastrinaemia develops. The possible importance of the changes in pH of abomasal contents in the parasitism is indicated by demonstrations in the dog (Becker, Reeder & Thompson, 1973) that plasma gastrin increased when the antrum was perfused with solutions at or above pH 4, and experiments in sheep showing that acidification of antral pouches to pH 2-7 or less reduced HC1 secretion of pouches of the parietal cell region of the abomasum (McLeay & Titchen, 19776). Although data from the dog cannot be directly applied to sheep it should be noted that whereas plasma gastrin rose in the dog to 1-5 times resting levels with antral perfusions at pH 7-0, in the sheep plasma gastrin increased 5-to 20-fold during ostertagiasis.…”