Physiological antagonism between PGE2, PGA1, PGF1-alpha and NADP, beta-NAD on isolated rabbit jejunum.

The antagonistic action between the prostaglandins PGE2, PGA1 and PGF1-alpha, on the one hand, and nicotinamide-adenine-dinucleotide-phosphate (NADP or TPN) and beta-nicotinamide-adenine-dinucleotide (beta-NAD or DPN) on the other, were experimentally studied on rabbit isolated jejunum. Our results support our previously expressed hypothesis that in the living organism there exist regulatory systems to control the actions of extremely potent substances such as the PGs. NADP and beta-NAD may therefore be grouped together with AMP, ADP and ATP as naturally occurring compounds that antagonise the actions of PGs.