The effect of vasopressin on fetal oxygenation in sheep.

Abstract

To examine the effects of vasopressin on fetal oxygenation the hormone was infused intravenously for 1 h (1.4-3.5 mU X min-1 X kg fetal weight-1) to chronically catheterized fetal lambs in utero (113-137 days gestation). Arterial pressure rose (48.3 to 59.6 mmHg) (1 mmHg = 133.322 Pa) and heart rate fell (185.3 to 141.0 beats/min) during the infusion. There was a significant increase in fetal arterial PO2 (20.0 to 23.1 mmHg) and significant declines in pH (7.414 to 7.381) and base excess. Umbilical blood flow rose, and the percentage increase in flow (23%) was identical to the proportional rise in arterial pressure. Accompanying the rise in umbilical blood flow was a rise in umbilical oxygen delivery. But as there was no change in fetal oxygen consumption, fractional oxygen extraction by the fetus fell significantly (0.31 to 0.25). These data indicate that the vasopressin-induced rise in fetal vascular PO2 results from an increase in umbilical oxygen delivery and concomitant fall in fractional extraction. Fetal vasopressin levels are greatly elevated during hypoxia, and under conditions of reduced oxygen supply, the effects of the hormone on umbilical oxygen delivery and vascular PO2 could have definite survival value.

• Authors: D W Rurak, N C Gruber
• Journal: Canadian journal of physiology and pharmacology (Can J Physiol Pharmacol) Vol. 62 Issue 1 Pg. 27-30 (Jan 1984) ISSN: 0008-4212 [Print] Canada
• PMID: 6424915 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Vasopressins
• Carbon Dioxide
• Oxygen

Topics

• Animals
• Blood Pressure (drug effects)
• Carbon Dioxide (blood)
• Female
• Fetus (drug effects, metabolism)
• Heart Rate (drug effects)
• Hydrogen-Ion Concentration
• Oxygen (blood)
• Oxygen Consumption (drug effects)
• Pregnancy
• Sheep
• Umbilical Cord (physiology)
• Vasopressins (pharmacology)