Increased Expression of Ornithine Decarboxylase in Distal Tubules of Early Diabetic Rat Kidneys Are

Polyamines are small biogenic molecules that are essen-tial for cell cycle entry and progression and prolifera-tion. They can also contribute to hypertrophy. The activity of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, increases in the early diabetic kidney to enable renal hypertrophy. Inhibition of ODC in early diabetes attenuates diabetic renal hypertrophy and glomerular hyperfiltration. The current studies examine the temporal profile of renal ODC protein expression and localization, intrarenal polyamine levels, and sites of proliferation in kidneys of rats during the first 7 days of streptozotocin diabetes. ODC mRNA and protein content were increased in diabetic kidneys. High-performance liquid chromatogra-phy analysis showed increased intrarenal polyamin