Increased iNOS activity in vascular smooth muscle cells from diabetic rats: potential role of Ca(2+)/calmodulin-dependent protein kinase II delta 2 (CaMKIIδ(2))

Inducible nitric oxide synthase (iNOS) expression may be increased by cytokine plasma levels contributing to vascular damage in diabetes. Besides transcriptional regulation, Ca(2+)/CaMKII may play a role in post-translationally controlled iNOS activity. We accordingly investigated the involvement of the Ca(2+)/CaMKIIδ(2) signaling pathway in regulating lipopolysaccharide (LPS)-induced iNOS activity in cultured aortic vascular smooth muscle cells (VSMCs) from diabetic rats. VSMCs obtained from 10 diabetic rats (DR) and 10 control rats (CR) were stimulated with 20 μg/ml LPS. After 24 h, iNOS protein levels were 1.37 fold increased in DR- vs CR-VSMCs (p