Renal hemodynamic effects of oxytocin in antepartal and postpartal women

Renal clearances (C IN , C CR , C PAH , C H 2 O , and C OSM ) were performed in 12 antepartal and 14 postpartal healthy, hydrated subjects during periods of 0, 20, 100, and 1,000 mU. per minute of oxytocin. The antidiuresis which resulted from oxytocin infusions was found to be due to absorption of water from the renal distal convoluted tubules and collecting ducts. Slight decreases in C IN , C CR , and C PAH were demonstrated during most of the oxytocin infusions, but these are believed to have been caused principally by the relatively large urinary "dead space" and low flow rates. We do not believe that the glomerular filtration rate or renal plasma flow is materially affected by oxytocin, even in doses as large as 1,000 mU. per minute.