Renal kallikrein in human and experimental diabetes mellitus.

Urinary kallikrein excretion was studied in a group of insulin-dependent diabetic patients in relation to glycemic control, and both urinary and renal tissue levels of kallikrein were measured in untreated and insulin-treated streptozotocin-diabetic rats. While on a fixed normal sodium diet, diabetic patients in poor glycemic control (HbA1c greater than 11%) showed elevated urinary kallikrein, compared to patients with HbA1c less than 11% or normal subjects. Strict glycemic control lowered kallikrein excretion in diabetic patients. In contrast, severely hyperglycemic diabetic rats had reduced urinary and renal kallikrein levels, compared to nondiabetic control rats, and the reduction in urinary kallikrein preceded the development of systolic hypertension. Insulin treatment normalized urinary kallikrein in diabetic rats, but resulted in increased renal kallikrein levels compared to nondiabetic rats. The differences in kallikrein abnormalities observed in diabetic patients and a diabetic animal model may possibly be related to renal hemodynamic changes in clinical and experimental diabetic states.