GASTRIC-ACID SECRETION IN THE CHICKEN - EFFECT OF HISTAMINE H(2) ANTAGONISTS AND H+ K+-ATPASE INHIBITORS ON GASTROINTESTINAL PH AND OF SEXUAL MATURITY CALCIUM-CARBONATE LEVEL AND PARTICLE-SIZE ON PROVENTRICULAR H+/K+ ATPASE ACTIVITY/
F. Guinotte et al., GASTRIC-ACID SECRETION IN THE CHICKEN - EFFECT OF HISTAMINE H(2) ANTAGONISTS AND H+ K+-ATPASE INHIBITORS ON GASTROINTESTINAL PH AND OF SEXUAL MATURITY CALCIUM-CARBONATE LEVEL AND PARTICLE-SIZE ON PROVENTRICULAR H+/K+ ATPASE ACTIVITY/, Comparative biochemistry and physiology. Part A, Physiology, 106(2), 1993, pp. 319-327
1. Cimetidine was more potent 4 hr after a single injection of 25 or 1
00 mg/kg body wt in increasing gastric pH than other H-2 receptor anta
gonists, ranitidine and famotidine but was less efficient than H+/K+-A
TPase inhibitors. Omeprazole rose proventricular and gizzard pH at a l
ower dose than SCH 28080 and Ro 18-5364 (30, 50 and 200 mg/kg body wt,
respectively). 2. Proventricular and gizzard pH values were maximal 1
and 4 hr after a single injection of 7.5 mumol/kg body wt omeprazole.
Inhibition of acid secretion was maintained for 24 hr after an inject
ion of 100 mumol/kg. 3. H+/K+-ATPase activity in vitro was 10 mumol P(
i)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. 4. 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 pul
lets or laying hens enhanced the H+/K+-ATPase activity when compared w
ith ground particles.