Stimulation of acid secretion and phosphoinositol production by rat parietal cell muscarinic M sub 2 receptors

Journal Article · Fri Apr 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:7014831

Pfeiffer, A; Rochlitz, H; Herz, A; Paumgartner, G ^[1]

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1. Univ. of Munich (West Germany)

The muscarinic receptor system involved in hydrogen production by enriched rat gastric parietal cells was investigated. Muscarinic receptor density determined by (N-methyl-{sup 3}H)scopolamine binding was 8,100/cell. The receptor appeared to be of the M{sub 2} muscarinic receptor subtype, since it had a low affinity (K{sub d} 189 nM) for the M{sub 1} receptor antagonist pirenzepine compared with atropine. Receptor activation by carbachol rapidly augmented levels of polyphosphoinositides, indicating an activation of phospholipase C. The dose-response relations for the increase in inositol phosphates closely paralleled the binding of carbachol to muscarinic receptors. The inositol phosphate response was antagonized by pirenzepine with a K{sub i} of 177 nM. the stimulation of inositol phosphate levels by carbachol correlated well with the stimulation of ({sup 14}C)aminopyrine uptake, determine as an index of acid secretion. The muscarinic agonists oxotremorine, pilocarpine, and bethanechol elicited partial increases in inositol phosphates at maximal drug concentrations, and these partial increases correlated with their ability to stimulate ({sup 14}C)aminopyrine uptake. These data indicate that inositolpolyphosphates may be a second messenger of M{sub 2} receptors stimulating acid secretion.

• OSTI ID: 7014831
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:4; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
AMINES
ANIMAL CELLS
ANIMALS
ATROPINE
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BODY FLUIDS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLESTERASES
CHARGED PARTICLES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ENZYMES
ESTERASES
GASTRIC ACID
HYDROGEN COMPOUNDS
HYDROLASES
INOSITOLS
IONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPASES
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MONOSACCHARIDES
ORGANIC COMPOUNDS
PARASYMPATHOLYTICS
PROTEINS
RADIORECEPTOR ASSAY
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SACCHARIDES
SECRETION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES