Gastric acid secretion in the chicken: effect of histamine H2 antagonists and H+/K+-ATPase inhibitors on gastro-intestinal pH and of sexual maturity calcium carbonate level and particle size on proventricular H+/K+ ATPase activity
1993
Guinotte, F. | Gautron, J. | Soumarmon, A. | Robert, J.C. | Peranzi, G. | Nys, Y.
Cimetidine was more potent 4 hr after a single injection of 25 or 100 mg/kg body wt in increasing gastric pH than other H2 receptor antagonists, ranitidine and famotidine but was less efficient than H+/K+-ATPase inhibitors. Omeprazole rose proventricular and gizzard pH at a lower dose than SCH 28080 and Ro 18-5364 (30, 50 and 200 mg/kg body wt, respectively). Proventricular and gizzard pH values were maximal 1 and 4 hr after a single injection of 7.5 micromole/kg body wt omeprazole. Inhibition of acid secretion was maintained for 24 hr after an injection of 100 micromole/kg. H+/K+-ATPase activity in vitro was 10 micromole Pi/hr/mg protein in the microsomal fractions of the proventriculus. It was doubled by nigericine and inhibited by SCH 28080. However, western blots by high specific H+/K+-ATPase monoclonal antibody 95-A3 and 95-111 recognized a 42 kDa band but hardly exhibited the specific 95 kDa band recognition. Chickens and immature pullets showed a higher H+/K+-ATPase activity than laying hens. Calcium level of the diet did not affect the enzyme activity but coarse particles of calcium fed to pullets or laying hens enhanced the H+/K+-ATPase activity when compared with ground particles.
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