Vasopressin transiently stimulates phospholipase C activity in cultured rat hepatocytes.
Vasopressin stimulated phospholipase C activity in primary cultures of rat hepatocytes maintained for 18-24 h under serum free conditions. Soluble and membrane-associated phospholipase C activity was determined using exogenous [3H]phosphatidylinositol 4,5-bisphosphate ([3H]PIP2) in the presence of cholate, deoxycholate and NaCl. Exposure of hepatocytes for 5 s to vasopressin (100 nM) stimulated both membrane-associated and soluble phospholipase C activity by 30% and 40%, respectively. However, by 15 s this stimulation had disappeared. Addition of vasopressin to hepatocytes, previously labelled with [3H]inositol, stimulated inositol phosphate production within 5 s, but little further increase was seen over a 5-min incubation. These results indicate that vasopressin rapidly stimulates both soluble and membrane-associated phospholipase C activity.
Pittner
R A
RA
Department of Biochemistry, University of Tennessee, Memphis 38163.
Fain
J N
JN
D015720:5'-Nucleotidase; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D003840:Deoxycholic Acid / Q000494:pharmacology; D007295:Inositol Phosphates / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D009708:Nucleotidases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D010738:Type C Phospholipases / Q000378:metabolism*; D014667:Vasopressins / Q000494:pharmacology*
D007295:Inositol Phosphates; D003840:Deoxycholic Acid; D014667:Vasopressins; D007770:L-Lactate Dehydrogenase; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D009708:Nucleotidases; D015720:5'-Nucleotidase; D010738:Type C Phospholipases