The Effect of Water Diuresis on Renal Plasma Flow

Ketone bodies increase glomerular filtration rate in normal man and in patients with type 1 (insulin-dependent) diabetes mellitus

The purpose of this study was to investigate whether the administration of acetoacetic and hydrochloric acids in a group of control and Type 1 (insulin-dependent) diabetic patients influenced renal haemodynamics. Renal plasma flow increased from 657 +/- 88 to 762 +/- 81 ml X min-1. 1.73 m-2 in diabetic patients (p less than 0.01) and from 590 +/- 71 to 691 +/- 135 in control subjects (p less than 0.01). Glomerular filtration rate increased from 135 +/- 9 to 180 +/- 8 ml X min-1. 1.73 m-2 in diabetic patients (p less than 0.001) and from 117 +/- 8 to 145 +/- 7 in control subjects (p less than 0.01). Similar effects on renal haemodynamics, even if less pronounced, were observed with low dose acetoacetic but not with hydrochloric acid infusion. Total protein, beta 2-microglobulin but not albumin excretion rates were increased by acetoacetic acid. We conclude that an acute increase in blood concentration of ketone bodies within the range found in diabetic patients with poor metabolic control increases renal plasma flow and glomerular filtration rate both in control subjects and diabetic patients and causes a tubular proteinuria.

A comparison of the effects of intravenous propranolol and nadolol on the renal response to hypertonic saline infusion

Intravenous loading with 500 ml of 2.7% saline increased the clearance of PAH and inulin and urine sodium excretion in 14 healthy subjects. Intravenous propranolol (0.075 and 0.15 mg/kg) did not alter PAH or inulin clearance at rest but abolished the increase expected during saline infusion. There was no consistent effect on urinary sodium excretion. Intravenous nadolol (0.05 and 0.75 mg/kg) reduced resting PAH and inulin clearances by up to 25%. Both clearances fell significantly during saline infusion but natriuresis was not significantly reduced in spite of the changes in renal function. There was no evidence from these studies in normal volunteers that nadolol confers any advantages over propranolol in its effects on renal function.