Effects of indomethacin in conscious dogs with experimental high-output heart failure.

The role of renal prostaglandins in the control of renin release and renal hemodynamic function (RHF) was studied in conscious dogs with a surgically created infrarenal aortocaval fistula, a model of high-output heart failure (HOHF). In series 1 during acute cardiac failure, indomethacin administration produced striking reductions in RHF but failed to alter the high level of plasma renin activity (PRA). In series 2, administration of indomethacin to dogs with chronic HOHF also resulted in pronounced decrements in RHF in spite of normal levels of PRA. Studies of individual animals with meclofenamate in both series 1 and 2 confirmed the findings with indomethacin with one exception; in one dog with chronic severe HOHF a very high level of PRA was present initially and fell 44% after meclofenamate. These observations indicate that in the acute and chronic phases of HOHF prostaglandins are involved in the maintenance of renal blood flow and glomerular filtration rate but do not play an essential role in the control of renin release.