Effects of acetaminophen and ibuprofen on renal function in anesthetized normal and sodium-depleted dogs

In certain conditions, renal prostaglandins (PGs) are important determinant s of kidney function. Under these "renal PG-dependent states," pharmacologi cal inhibition of vasadilatory PG may result in excessive renal vasoconstri ction and adversely affect kidney function. The purposes of this study were to determine whether acetaminophen (Acet), a weak PC-synthesis inhibitor, influences kidney function in the renal PC-dependent state of anesthesia an d sodium depletion. Comparisons were made with ibuprofen (Ibu). Measurement s of PGE(2) excretion were used to assess renal PG synthesis. Acet (15 mg/k g) and Ibu (10 mg/kg) both decreased renal blood flow and glomerular filtra tion rate by similar to 20-30% in normal, anesthetized, sodium-replete dogs . Although Acet produced similar changes in renal blood flow and glomerular filtration rate in the low-sodium dogs, Ibu caused a significantly greater renal vasoconstriction (64 +/- 10%) in these animals. Both Acet and Ibu in hibited urinary PGE(2) excretion in sodium-replete and low-sodium dogs. Ibu tended to have a greater and more prolonged effect than did Acet. These re sults suggest that-Acet alters PGE(2) excretion and kidney function under r enal PC-dependent conditions; the effects, however, are less severe than th ose seen with Ibu.