Mass spectrometric evidence for the conversion of exogenous adrenate to dihomo-prostaglandins by seminal vesicle cyclo-oxygenase. A comparative study of two animal species.
We present conclusive mass spectrometric evidence for the synthesis of 1a,1b-dihomoprostaglandin E2 and 1a,1b-dihomoprostaglandin F2 alpha by sheep seminal vesicle microsomes and swine whole vesicular homogenates. Swine microsomes prepared according to standard procedure were catalytically inactive, possibly due to autoinactivation of the cyclo-oxygenase caused by metabolism of endogenous substrate released during the isolation procedure. Cyclo-oxygenase activity could be demonstrated, however, when the porcine vesicles were homogenized in the presence of exogenous substrate. Chemical and mass spectrometric evidence presented here allow unequivocal structural assignments.
D000818:Animals; D001711:Biotransformation; D015237:Dinoprost / Q000031:analogs & derivatives*; D015232:Dinoprostone / Q000031:analogs & derivatives*; D004883:Erucic Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D066298:In Vitro Techniques; D008297:Male; D013058:Mass Spectrometry; D008861:Microsomes / Q000201:enzymology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011458:Prostaglandins E / Q000378:metabolism*; D011460:Prostaglandins F / Q000378:metabolism*; D012669:Seminal Vesicles / Q000201:enzymology*; D012756:Sheep; D013045:Species Specificity; D013552:Swine
D004883:Erucic Acids; D005231:Fatty Acids, Unsaturated; D011458:Prostaglandins E; D011460:Prostaglandins F; C011395:adrenic acid; C024113:1a,1b-dihomoprostaglandin E2; C011447:1a,1b-dihomoprostaglandin F2; D015237:Dinoprost; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone