Effects of prostacyclin (PGI2) and indomethacin on neonatal lamb mesenteric and renal artery responses to electrical stimulation and norepinephrine.

The effects of prostacyclin (PGI2) and indomethacin on isolated neonatal lamb mesenteric and renal artery responses to electrical stimulation and injected norepinephrine were investigated. PGI2 (1 micro M) decreased baseline tension and significantly reduced vasoconstrictor responses to electrical stimulation and norepinephrine. Indomethacin raised baseline tension and potentiated the constrictor responses. PGI2 reversed completely the potentiating effects of indomethacin. These results suggest that PGI2 may modulate the response to adrenergic stimuli in the mesenteric and renal arteries of neonatal lambs.