Elevated endogenous Na-K-ATPase inhibitor activity in hypertensive diabetic patients with a family history of hypertension.

Digitalis-like substance (DLS) was measured by Na-K-ATPase inhibitor (ATPI) activity and digitalis-like immunoreactivity (DLI) in 100 patients with type II diabetes. Hypertensive diabetic patients with a positive family history for hypertension had high ATPI levels compared with those patients with a negative family history for the disease. DLI level did not differ between groups. There was no significant difference in ATPI and DLI levels among three groups based on level of urinary albumin excretion. These data suggest that a circulating factor (or circulating factors) determined by ATPI may be linked with genetic factors in the development of hypertension, but not to the development of diabetic nephropathy.