Effect of indomethacin on the glomerular filtration rate after a protein meal in humans.

Abstract

The renal response to a protein meal has been characterized by increases in glomerular filtration rate (GFR) and renal plasma flow and decrease in renal vascular resistance. Several hormonal mediators of this response have been proposed, including renal prostaglandins (PGs). We studied ten normal subjects before and after ingestion of indomethacin. All subjects had three 30-minute baseline creatinine and iothalamate clearances measured before and three one-hour clearances measured after an 80-g protein meal. The night before the second test, the subjects took 25 mg indomethacin and 150 mg one hour before the test meal. Urine PG excretion decreased significantly during the second test, from 0.60 +/- 0.23 to 0.30 +/- 0.14 ng/min (P less than 0.01). Initial iothalamate clearance increased from 110 +/- 10 to a mean of 122 +/- 15 mL/min/1.73 m2 (average increase of 12 mL/min/1.73 m2) during the second hour after the test meal. After ingestion of indomethacin, the GFR remained unchanged from a baseline of 101 +/- 9 to 101 +/- 7 mL/min/1.73 m2 (average change of -1 mL/min/1.73 m2). Because the time of peak increase after the meal varied from subject to subject, the maximal increase in GFR after the meal was calculated and found to be significantly less during the second test, 13 +/- 3 v 22 +/- 4 mL/min/1.73 m2 (P less than 0.05). Because PGs can stimulate glucagon secretion and because glucagon has been suggested to mediate the protein-stimulate GFR response, we measured plasma glucagon during both tests; these levels were not different.(ABSTRACT TRUNCATED AT 250 WORDS)