Calcium-dependent protein kinase activity is decreased in diabetic rat sciatic nerve.
The effects of 4 weeks of streptozotocin-induced diabetes in the rat on sciatic nerve homogenate protein kinase activities were studied. There was a 47 +/- 7% inhibition of Ca+2-dependent protein kinase activity in nerves from the diabetic rats compared to that in their paired normal controls. This Ca+2-dependent activity did not require the addition of phospholipid and was only minimally affected by Sephadex G-50 gel filtration, suggesting that endogenous phospholipid activation was not responsible for this activity. The addition of phospholipid in the presence of Ca+2 revealed an additional activity in these homogenates which probably represents the Ca+2-phospholipid-dependent protein kinase (protein kinase-C). The diabetic state did not appear to alter that activity. The Ca+2-dependent protein kinase was sensitive to agents known to inhibit calmodulin-dependent protein kinase or protein kinase-C. The IC50 values of the inhibitors for the Ca+2-dependent protein kinase, however, differed from those reported for the other two kinases.
Gabbay
R A
RA
Department of Medicine, State University of New York Health Science Center, Brooklyn 11203.
Siconolfi-Baez
L
L
Lebovitz
H E
HE
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002850:Chromatography, Gel; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D010718:Phosphatidylserines / Q000494:pharmacology; D010743:Phospholipids / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011112:Polymyxin B / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000201:enzymology*; D013449:Sulfonamides / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D004075:Diglycerides; D007546:Isoquinolines; D010718:Phosphatidylserines; D010743:Phospholipids; D010879:Piperazines; D013449:Sulfonamides; D014268:Trifluoperazine; C017967:W 7; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D011112:Polymyxin B; D002118:Calcium; C013965:diolein