[Effect of Tujian decoction on protein kinase C activity in renal cortex in diabetic rat].

Objective: To investigate influence of administration of Tujian decoction (Chinese herbal medicine) on protein kinase C (PKC) activity, renal function and structure in diabetic rat kidney.

Method: Experimental diabetic nephropathy model was induced by nephrectomy combined with streptozotocin (STZ) injection in sprague-dawley rat. Tujian decoction (20 g x kg(-1) x d(-1)) and Valsartan (20 mg x kg(-1) x d(-1)) were orally administrated respectively for 12 weeks. PKC activity was measured by [3H]phorbol 12, 13-dibutyrate ([3H]PDBu) binding assay. 24 h urine protein excretion (Upro) and renal pathological changes were observed.

Result: In 12th week, diabetic nephrectomized rats developed proteinuria, glomerulosclerosis, increased membrane PKC activity (mPKC), decreased cytosol PKC (cPKC), and increased ratio of mPKC and cPKC (M/C). Administration of Tujian decoction or Valsartan led to a reduction in proteinuria, structural injury, mPKC and M/C, and a recovery in cPKC.

Conclusion: Tujian decoction possesses a renoprotective effect on diabetic nephrectomized rat, at least partially via the inhibition of PKC activation in renal cortex.