Comparative study of the control of basal acid output from rodent isolated stomachs.
1. Isolated, lumen-perfused, whole stomach preparations from mouse and immature rat produced a stable basal acid output which, although not blocked by histamine H2-, acetylcholine M- or CCKB/gastrin receptor antagonists, was almostly completely blocked by the H+/K(+)-ATPase inhibitor, omeprazole, and the metabolic inhibitor, sodium thiocyanate (NaSCN). 2. Fully-defined concentration-effect curves could be obtained on both assays with the phosphodiesterase inhibitor, isobutyl methylxanthine (IBMX) and with dibutyryl cyclic AMP. 3. On the rat stomach assay, histamine H2-receptor blockade had no effect on the IBMX curve. In contrast, the IBMX response in the mouse was abolished by histamine H2-receptor blockade. On both assays responses to dibutyryl cyclic AMP were resistant to H2-receptor blockade. 4. In the absence of suprathreshold endogenous histamine, it is argued that H+/K(+)-ATPase mediated basal acid secretion from the mouse stomach assay is regulated by something other than cyclic AMP.
Welsh
N J
NJ
Department of Analytical Pharmacology, Rayne Institute, King's College School of Medicine and Dentistry, London.
Shankley
N P
NP
Black
J W
JW
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D054328:Proton Pump Inhibitors; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000502:physiology*; D013861:Thiocyanates / Q000494:pharmacology
D006635:Histamine H2 Antagonists; D010726:Phosphodiesterase Inhibitors; D054328:Proton Pump Inhibitors; D013861:Thiocyanates; C024553:sodium thiocyanate; D003994:Bucladesine; D006632:Histamine; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine