Abstract
Prostaglandins may be important in regulation of the postnatal decrease in pulmonary vascular resistance (PVR). We investigated the effect of PGD2 on PVR in 5 unanesthetized near term lambs delivered by ceasarean section. Under local anesthesia tracheostomy and ductal ligation were performed; left and right atrial, pulmonary arterial (PA) and aortic (AO) catheters were placed, and an electromagnetic PA flow transducer was positioned. The lambs received 5 mg indomethacin during and at the end of surgery. They were ventilated with a mixture of air and N2 to produce P02′s in the 10-36 torr range. All lambs developed pulmonary hypertension with PA equal to AO pressure. They were given bolus injections into the PA of PGD2 in increments of 0.1 - 100 ugs. Each exhibited a dose related fall in PA pressure and increase in cardiac output (CO) without change in AO pressure. At 20 ugs, beyond which there was little change in effect, PA pressure fell by 28.7 ± 10.2% SE, CO increased by 48.3 ± 28.2%, and AO pressure increased by 3.1 ± 8.3%. At all doses PVR fell further than systemic vascular resistance (SVR). At the 20 ug dose PVR fell by 51.9 ± 13.3% while, SVR fell by 29.2 ± 12.5% due to the large increase in CO. Under these conditions PGD2 has a powerful and specific effect on PVR. This specificity may be important in the regulation of PVR at birth and in treatment of persistent pulmonary hypertension.
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Soifer, S., Morin, F., Roman, C. et al. 1433 PROSTAGLANDIN D2 (PGD2) DECREASES HYPOXIC PULMONARY HYPERTENSION IN NEWBORN LAMBS. Pediatr Res 15 (Suppl 4), 682 (1981). https://doi.org/10.1203/00006450-198104001-01462
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DOI: https://doi.org/10.1203/00006450-198104001-01462