Renal Hemodynamic Abnormalities in Patients with Short Term Insulin-Dependent Diabetes Mellitus: Role of Renal Prostaglandins*

To determine if renal functional alterations in diabetes mellitus could be related to disturbances of vasoactive systems, renal plasma flow (RPF), glomerular filtration rate (GFR), PRA (basal and stimulated), plasma catecholamine levels, and urinary excretion of prostaglandin E2 (PGE2), 6-keto-PGF1 alpha, and kallikrein were determined in 21 patients with insulin-dependent diabetes mellitus (IDDM) of short duration and 15 normal subjects. In 7 additional patients with IDDM and in 4 normal subjects, the effect of lysine acetylsalicylate (LAS; 450 mg, iv) on GFR and RPF was studied. Patients with IDDM had higher RPF and GFR than normal subjects. Plasma norepinephrine and basal and stimulated PRA were significantly lower in IDDM than in the control group [161 +/- 82 (+/- SD) vs. 243 +/- 114 pg/ml, 0.19 +/- 0.20 vs. 1.15 +/- 0.33 ng/ml X h, and 0.93 +/- 0.82 vs. 2.8 +/- 1.73 ng/ml X h, respectively). No significant differences were found in the urinary excretion of PGE2, 6-keto-PGF1 alpha, and kallikrein in the two groups. LAS administration significantly reduced RPF (from 641 +/- 72 to 535 +/- 38 ml/min X 1.73 m2) and GFR (from 168 +/- 25 to 150 +/- 18 ml/min X 1.73 m2) in patients with IDDM, but not in normal subjects. In IDDM patients, there was a close direct correlation between the percent decrease in RPF and GFR induced by LAS and the baseline values of these parameters. The results suggest that in IDDM, there may be an imbalance between the degree of activation of the renin-angiotensin and sympathetic nervous systems and the renal production of PGs. The observation that LAS administration reduced RPF and GFR in these patients suggests that renal PGs are involved in the renal hyperperfusion of IDDM.