Effect of diabetes on calcium/calmodulin dependent protein kinase-II from rat brain.

Changes in the protein levels and activity of Ca2+/Calmodulin dependent protein kinase II (CaM kinase II) level were studied in cytosolic and particulate fractions from cerebral hemisphere, cerebellum, brain stem, thalamus and hypothalamus regions of rat brain after 4 and 12 weeks of induction of diabetes. Streptozotocin induced diabetes, resulted in pronounced increase of CaM kinase II activity as determined by the kinase activity assay. The total amount of enzyme protein (alpha-subunit specific) also showed increase as revealed by western blotting. Parallel studies were also made in age matched control rats and insulin treated diabetic rats. The increase in CaM kinase II activity was more pronounced in the 12 weeks diabetic group. Insulin treatment of diabetic rats, resulted in recovery of enzyme activity near to control values from majority of the brain regions studied. The expression of alpha-subunit specific CaM kinase II correlates with the enzyme activity in the diabetic rat brain.