Reduced sodium pump activity in inositol-deficient HL-60 cells: no evidence of control by protein kinase C.
HL-60 cells were cultured in normal and inositol-deficient media. The inositol-deficient cells showed reduced sodium pump activity, as measured by ouabain-sensitive 86Rb+ uptake. The protein kinase C inhibitors staurosporine and H7 did not affect uptake in either normal or inositol-deficient cells. However, U73122, a steroidal inhibitor of phosphoinositidase C, inhibited uptake in both types of cells. Activators of protein kinase C had no effect on Rb+ entry. The inositol deficiency is not considered to affect the sodium pump by a mechanism involving diacylglycerol and protein kinase C.
Allard
J
J
Department of Biochemistry, Medical School, Queen's Medical Centre, Nottingham, UK.
Lennon
D P
DP
Greenwood
M R
MR
Buckenham
A J
AJ
Hawthorne
J N
JN
D006801:Humans; D007294:Inositol / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D007294:Inositol; D010042:Ouabain; D011493:Protein Kinase C; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium