Studies in vitro on the effect of adenosine, adenine and NAD on guinea pig myometrium in the presence of exogenously applied PGE2.

In guinea pig isolated uterine strips, separate addition of adenosine, adenine and NAD was without any effect. Adenosine and NAD when administered after previously applied subthreshold dose of PGE2 exhibited a strong contractile effect. Indomethacin, added to the organ bath before addition of prostaglandin, blocked, partially or totally, the observed synergistic action of PGE2 with adenosine and NAD. From the experimental data of the present work it is postulated that adenosine and NAD stimulate prostaglandin biosynthesis in myometrium as already it has been suggested for ATP, ADP and AMP. The aspect for the existence of a functional link between adenyl compounds and prostaglandins, based on these findings, is reinforced.