Prostaglandins in the human endometrium. Gas chromatographic-mass spectrometric quantitation before and after IUD...

Prostaglandin F2alpha and its major metabolite in plasma, 15-keto-13, 14-dihydro-PGF2alpha were quantitated in biopsies from human endometrium using gas-liquid chromatography-mass spectrometry. In four of the five cases studied, the levels of both compounds were higher in the secretory phase than in the proliferative phase regardless of whether the IUD was present or not. Before insertion of an IUD the levels of PGF2alpha ranged from 65 to 8,280 pg. per milligram of tissue and those of 15-keto-13,14-dihydro-PGF2alpha ranged from less than 4 to 1,940 pg. per milligram. After insertion of an IUD the levels of the compounds ranged from 260 to 2,100 and from 5 to 109 pg. per milligram, respectively. In four of the five individual cases the IUD caused a decrease rather than an increase of the prostaglandin content of the tissue. These data do not indicate an increased biosynthesis of prostaglandins in the human endometrium after insertion of an IUD.