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.
1. 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). 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 injection of 100 mumol/kg. 3. H+/K(+)-ATPase activity in vitro was 10 mumol 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. 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 pullets or laying hens enhanced the H+/K(+)-ATPase activity when compared with ground particles.
Guinotte
F
F
Station de Recherches Avicoles, INRA Centre de Tours, Nouzilly, France.
Gautron
J
J
Soumarmon
A
A
Robert
J C
JC
Peranzi
G
G
Nys
Y
Y
D000818:Animals; D002119:Calcium Carbonate / Q000378:metabolism*; D002645:Chickens / Q000502:physiology*; D004032:Diet; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D009853:Omeprazole / Q000494:pharmacology; D010316:Particle Size; D012741:Sexual Maturation; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*
D006635:Histamine H2 Antagonists; D000254:Sodium-Potassium-Exchanging ATPase; D002119:Calcium Carbonate; D009853:Omeprazole