Effect of verapamil on cardiac protein kinase C activity in diabetic rats.
We examined the effect of verapamil treatment on cardiac protein kinase C (PKC) activity in streptozocin-induced diabetic rats. Basal cardiac PKC activity in diabetes increased in both cytosolic (by 94%, P less than 0.01) and membrane (by 41%, P less than 0.05) fractions as compared with that in controls. Subcutaneous administration of 8 mg/kg verapamil twice a day for 8 weeks induced a significant decrease in both cytosolic (by 59%, P less than 0.01) and membrane (by 50%, P less than 0.01) PKC activity in diabetes as compared with the activity in the non-treated diabetic groups. In contrast, cardiac cytosolic PKC activity in control rats was significantly (P less than 0.01) decreased by 41% as compared with that of the non-treated control group without there being any change in membrane PKC activity. Our data demonstrate that verapamil treatment may ameliorate the abnormal activation of cardiac PKC in diabetes.
Tanaka
Y
Y
Third Department of Medicine, Shiga University of Medical Science, Otsu, Japan.
Kashiwagi
A
A
Ogawa
T
T
Abe
N
N
Asahina
T
T
Ikebuchi
M
M
Takagi
Y
Y
Shigeta
Y
Y
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D006352:Heart Ventricles / Q000033:anatomy & histology; D007328:Insulin / Q000097:blood; D008297:Male; D008566:Membranes / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D009929:Organ Size / Q000187:drug effects; D011493:Protein Kinase C / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology*
D001786:Blood Glucose; D007328:Insulin; D014700:Verapamil; D011493:Protein Kinase C