Activation of protein kinase C during cell volume regulation in Ehrlich mouse ascites tumor cells.
We have previously demonstrated that in Ehrlich cells a bumetanide-sensitive Na+,K+,2Cl- cotransporter is activated during regulatory volume decrease after cell shrinkage (hypertonic conditions) as well as during the late phase of regulatory volume decrease (hypotonic conditions). It is, however, quiescent under isotonic conditions. Using a protein kinase C assay system (Amersham, UK) it is here demonstrated that hypertonic cell shrinkage results in an increase in protein kinase C activity to 174% within the first minute, concomitant with the activation of the Na+,K+,2Cl- cotransporter. Hypotonic cell swelling results in a late activation of protein kinase C concomitant with a late activation of the Na+,K+,2Cl- cotransporter. The activation of protein kinase C during hypertonic as well as hypotonic conditions is inhibited by H-7. The more specific protein kinase C inhibitor chelerythrine inhibited protein kinase C as well as the Na+,K+,2Cl- cotransporter to the same extent as did H-7. These results indicate the involvement of protein kinase C in the regulation of the Na+,K+,2Cl- cotransporter in Ehrlich ascites tumor cells during cell volume regulation.
August Krogh Institute, University of Copenhagen, Denmark.
A K
AK
Larsen
B S
BS
Jensen
E K
EK
Hoffmann
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000470:Alkaloids; D000818:Animals; D053119:Benzophenanthridines; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology*; D002352:Carrier Proteins / Q000378:metabolism; D048429:Cell Size; D018118:Chloride Channels / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D006982:Hypertonic Solutions; D007038:Hypotonic Solutions; D007546:Isoquinolines / Q000494:pharmacology; D051379:Mice; D010617:Phenanthridines / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D014407:Tumor Cells, Cultured
D000470:Alkaloids; D053119:Benzophenanthridines; D002352:Carrier Proteins; D018118:Chloride Channels; D006982:Hypertonic Solutions; D007038:Hypotonic Solutions; D007546:Isoquinolines; D010617:Phenanthridines; D010879:Piperazines; D015221:Potassium Channels; D028021:Sodium-Potassium-Chloride Symporters; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C016299:chelerythrine; D011493:Protein Kinase C