Phorbol esters and A23187 regulate Na/sup +/=K/sup +/-pump activity in pancreatic acinar cells

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5716276

Hootman, S R; Brown, M E; Williams, J A

To clarify the subcellular mechanisms that mediate stimulation of Na/sup +/-K/sup +/-pump activity in pancreatic acinar cells by cholinergic agonists, the authors examined the effects of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) and the Ca/sup 2 +/ ionophore A23187 on (/sup 3/H)ouabain binding to dispersed guinea pig pancreatic acinar cells under conditions in which binding reflects the average rate of pump cycling. The phorbol ester more than doubled Na/sup +/-K/sup +/-pump activity as did the diacylglycerol analogue, 1-oleoyl-2-acetolyl-sn-3-glycerol. A23187 increased pump activity by a maximum of 31% at 0.3 ..mu..M but was progressively inhibitory at higher concentrations. The stimulatory effects of TPA and A23187 were additive, although either secretagogue elicited a less than additive response when added together with a maximally effective concentration of the cholinergic agonist, carbachol. Removal of extracellular Ca/sup 2 +/ had little effect on the pump response to TPA and did not reduce the maximal effect of A23187 but abolished the inhibitory effect seen at high ionophore concentrations in Ca/sup 2 +/-containing medium. These results indicate that both Ca/sup 2 +/ and protein kinase c are involved in regulating Na/sup +/-K/sup +/-pump activity in the pancreatic acinar cell.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 5716276
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:4; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARCINOGENS
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CHARGED PARTICLES
DIGESTIVE SYSTEM
DISACCHARIDES
DRUGS
ENDOCRINE GLANDS
ENZYMES
ESTERS
GLANDS
GLYCOSIDES
GUINEA PIGS
IONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
OUABAIN
PANCREAS
PHORBOL ESTERS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PHYSIOLOGY
POTASSIUM COMPOUNDS
RODENTS
SACCHARIDES
SACCHAROSE
SODIUM COMPOUNDS
SOMATIC CELLS
STROPHANTHINS
TRANSFERASES
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES