[The role of extra- and intracellular calcium in pepsinogen extrusion by isolated gastric glands].
It was found that carbacholine stimulated pepsinogen extrusion by isolated guinea pig stomach glands which were incubated in Ca(2+)-free medium, containing EGTA (0.25 mM). This effect could be imitated by caffeine (10 mM), a specific activator of Ca2+ release from intracellular pools. Extracellular Ca2+ in the concentrations over 0.125 mM increased pepsinogen extrusion which was stimulated by carbacholine. The interdependence between the level of pepsinogen extrusion and Ca2+ concentration in the medium had S-shaped character. La3+ ions (10(-4) mM) inhibited pepsinogen extrusion already in the first minutes after its activation by carbacholine. When testing other cations (Sr2+, Mg2+, Ba2+) it was found that only Sr2+ had some influence on pepsinogen extrusion. Thus, it can be concluded that both intra- and extracellular Ca2+ take part in the activation of pepsinogen extrusion. Obviously the role of extracellular Ca2+ consists in the support of reactivity of stomach glands to the action of stimulators of secretion.
Dubyts'kyĭ
L O
LO
Shostakovs'ka
I V
IV
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology* / Q000502:physiology*; D002217:Carbachol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004533:Egtazic Acid / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008673:Metals, Alkaline Earth / Q000494:pharmacology; D010435:Pepsinogens / Q000187:drug effects / Q000378:metabolism*; D010477:Perfusion / Q000379:methods
D008673:Metals, Alkaline Earth; D010435:Pepsinogens; D002110:Caffeine; D004533:Egtazic Acid; D002217:Carbachol; D002118:Calcium
Doslidzhennia roli zovnishn'o- i vnutrishn'oklitynnoho kal'tsiiu v ekstruziï pepsynohenu izol'ovanymy zalozamy shlunka.