<qa>  What is the enzyme in the body that has been implicated in the process of diabetic microProtein kinase C PKC, an enzyme in the body, has been implicated in the process of diabetic microvascular complications. The purpose of this study will be to evaluate the renal hemodynamic and peripheral vascular effects of PKC inhibition with ruboxistaurin mesylate an inhibitor of PKC in patients with Type 1 diabetes mellitus and evidence of early nephropathy. In this pilot study, 21 patients with type 1 diabetes were planned to be randomized to LY333531 or placebo in a 2:1 fashion, after an initial period of testing. After 8 weeks of study drug, patients were retested. 