15
PROSTAGLANDIN E AND F
CONCENTRATIONS IN HUMAN ENDOMETRIUM AFTER INSERTION OF
INTRAUTERINE CONTRACEPTIVE DEVICE KEITH HILLIER
J. M. KASONDE
Department of Physiology and Biochemistry, University of Southampton, and Nuffield Department of Obstetrics and
Gynœcology, University of Oxford The prostaglandin (P.G.) content of endometrium from fourteen women was examined before and 1-5 months after insertion of an intrauterine contraceptive device. A statistically significant increase in P.G.E but not P.G.F was observed. The P.G.E concentration increased in eleven of fourteen cases and fell in three. The P.G.F content increased in five cases and fell in eight.
Summary
Introduction THE mechanism of action of intrauterine contraceptive devices (l.U.D.S) is unknown.’ One theory implicates the local release of bioactive substances, and Chaudhuri has suggested that increased endometrial prostaglandins (P.G.) after I.V.D. insertion may be involved in the antifertility action of the device.2 This theory has not so far been supported by experimental evidence since I.V.D.S were found to cause no increase in endometrial p.G.F1cx or 15-keto-13, 14-dihydro-P.G.F, one of its principal metabolites. Animal studies, however, have shown that the insertion of an I.V.D. causes an increase in the prostaglandin content of the endometrium in many species.4-6 The uterine-vein prostaglandin concentrations in sheep with a fitted device also rose, causing premature luteolysis, and this could be prevented by treatment with prostag-
landin-synthetase inhibitors.4 The objective of this investigation was to determine whether human endometrial p.G.E1 and P.G.F2oc concentrations are altered by the presence of an LV.D. Materials and Methods Fourteen healthy women aged 20-36 years and parity 1-3 with regular menstrual cycles took part in the study with full and informed consent. Endometrial tissue was obtained with a vacuum aspiration curette (Rocket Ltd). Three strips of endometrium were taken. One sample was used for histological dating and one for other studies. A third strip, for P.G. assay, was immediately transferred to a preweighed vial and snap frozen in liquid nitrogen within 30s of removal. Samples were stored at -20°C until used. Samples were obtained before insertion of the I.U.D. and at approximately the same time in the cycle 1-5 months after insertion of the l.u.D.
8.
Baum, J. D., Weller, P. H., Barr, P. A., Gupta, J., Chung, C., Jenkins, P. A. Paper read at the "Intensive Care of the Newborn" Conference, held at Stavrby Skov, Middlefart, Denmark, in August, 1975. 9. Kanto, W. P., Borer, R. C., Roloff, D. W. J. Pediat. 1974, 84, 921. 10. Fox, H. A., Sarkozi, L., Rosenfeld, W. N. Pediat Res. 1974, 8, 446. 11. Borer, R. C., Gluck, L. Laboratory Schedule, Department of Pediatrics, University of San Diego, California, U.S.A., 1971. 12. Evans, J. J. New Engl. J. Med. 1975, 292, 1113. 13. Cowett, R. M., Unsworth, E. J., Hakanson, D. O., Williams, J. R., Oh, W. ibid. 1975, 293, 413.
Endometria from the same patient before and after I.U.D. insertion were always extracted in the same assay. Approximately 2500 degradations/min (d.p.m.) of 3H-p.G.E2 (specific activity 160 Ci/mmol) and 3H-p.G.F2IX (175 Ci/mmol) were added to the tissue (weight range 40-70 mg) to determine methodological losses. Extraction, chromatography, and assay were performed using a modofication of the method of Hillier and Dilley.’ The method now uses silicic-acid columns to separate p.G.E and P.G.F groups but with similar solvent conditions. Further characterisation ofp.G.Fs or P.G.Es other than group separation was not attempted, and the results are expressed as p.G.F2IX or p.G.E2 equivalents. Each chromatographed extract was assayed at three dilutions. The recoveries of 3H-P.G.F,oc and ’H-P.G.E, by this method were 71±6% (meanis.E.M., n=13) and 65±4-5% (n=14), respectively. The interassay coefficient of variation for P .G.F 2IX extraction from ovarian tissue by the same operator using exactly the same techniques was 8.5%. The inter-assay coefficient of variation for repeated estimates of a pooled plasma sample by the same operator was 10.6% for p.G.E and 18.8% for p.G.F and intra-assay coefficient of variation was 8.9% for p.G.E and 11.8% for p.G.F. The specificity of the assay was ensured by the completeness of column separation and the selectivity of the antibodies used.’ Cross-reactivity of the p.G.F2IX antibody (supplied by J. Hennam) was: P.G.F2IX, 100; P.G.F,a, 62.5; P.G.E,, 6.6; and
p.G.A2,0.1. p.G.E2 radioimmunoassay
was performed in a manner almost indentical to that for p.G.F2IX but using 15 000 d.p.m. 3H-p.G.E2 and an antibody prepared against p.G.E2 (supplied by the Worcester Foundation) with cross-reactivity as follows:
p.G.E2, 100; P.G.EI2 128; p.G.A2, 1.8; P.G.F2IX, 1-6; p.G.B2, Separation of major P.G. metabolites was achieved by the chromatographic step. Blank values were always non-detectable (
PROSTAGLANDIN E AND F
CONCENTRATIONS IN HUMAN ENDOMETRIUM AFTER INSERTION OF
INTRAUTERINE CONTRACEPTIVE DEVICE KEITH HILLIER
J. M. KASONDE
Department of Physiology and Biochemistry, University of Southampton, and Nuffield Department of Obstetrics and
Gynœcology, University of Oxford The prostaglandin (P.G.) content of endometrium from fourteen women was examined before and 1-5 months after insertion of an intrauterine contraceptive device. A statistically significant increase in P.G.E but not P.G.F was observed. The P.G.E concentration increased in eleven of fourteen cases and fell in three. The P.G.F content increased in five cases and fell in eight.
Summary
Introduction THE mechanism of action of intrauterine contraceptive devices (l.U.D.S) is unknown.’ One theory implicates the local release of bioactive substances, and Chaudhuri has suggested that increased endometrial prostaglandins (P.G.) after I.V.D. insertion may be involved in the antifertility action of the device.2 This theory has not so far been supported by experimental evidence since I.V.D.S were found to cause no increase in endometrial p.G.F1cx or 15-keto-13, 14-dihydro-P.G.F, one of its principal metabolites. Animal studies, however, have shown that the insertion of an I.V.D. causes an increase in the prostaglandin content of the endometrium in many species.4-6 The uterine-vein prostaglandin concentrations in sheep with a fitted device also rose, causing premature luteolysis, and this could be prevented by treatment with prostag-
landin-synthetase inhibitors.4 The objective of this investigation was to determine whether human endometrial p.G.E1 and P.G.F2oc concentrations are altered by the presence of an LV.D. Materials and Methods Fourteen healthy women aged 20-36 years and parity 1-3 with regular menstrual cycles took part in the study with full and informed consent. Endometrial tissue was obtained with a vacuum aspiration curette (Rocket Ltd). Three strips of endometrium were taken. One sample was used for histological dating and one for other studies. A third strip, for P.G. assay, was immediately transferred to a preweighed vial and snap frozen in liquid nitrogen within 30s of removal. Samples were stored at -20°C until used. Samples were obtained before insertion of the I.U.D. and at approximately the same time in the cycle 1-5 months after insertion of the l.u.D.
8.
Baum, J. D., Weller, P. H., Barr, P. A., Gupta, J., Chung, C., Jenkins, P. A. Paper read at the "Intensive Care of the Newborn" Conference, held at Stavrby Skov, Middlefart, Denmark, in August, 1975. 9. Kanto, W. P., Borer, R. C., Roloff, D. W. J. Pediat. 1974, 84, 921. 10. Fox, H. A., Sarkozi, L., Rosenfeld, W. N. Pediat Res. 1974, 8, 446. 11. Borer, R. C., Gluck, L. Laboratory Schedule, Department of Pediatrics, University of San Diego, California, U.S.A., 1971. 12. Evans, J. J. New Engl. J. Med. 1975, 292, 1113. 13. Cowett, R. M., Unsworth, E. J., Hakanson, D. O., Williams, J. R., Oh, W. ibid. 1975, 293, 413.
Endometria from the same patient before and after I.U.D. insertion were always extracted in the same assay. Approximately 2500 degradations/min (d.p.m.) of 3H-p.G.E2 (specific activity 160 Ci/mmol) and 3H-p.G.F2IX (175 Ci/mmol) were added to the tissue (weight range 40-70 mg) to determine methodological losses. Extraction, chromatography, and assay were performed using a modofication of the method of Hillier and Dilley.’ The method now uses silicic-acid columns to separate p.G.E and P.G.F groups but with similar solvent conditions. Further characterisation ofp.G.Fs or P.G.Es other than group separation was not attempted, and the results are expressed as p.G.F2IX or p.G.E2 equivalents. Each chromatographed extract was assayed at three dilutions. The recoveries of 3H-P.G.F,oc and ’H-P.G.E, by this method were 71±6% (meanis.E.M., n=13) and 65±4-5% (n=14), respectively. The interassay coefficient of variation for P .G.F 2IX extraction from ovarian tissue by the same operator using exactly the same techniques was 8.5%. The inter-assay coefficient of variation for repeated estimates of a pooled plasma sample by the same operator was 10.6% for p.G.E and 18.8% for p.G.F and intra-assay coefficient of variation was 8.9% for p.G.E and 11.8% for p.G.F. The specificity of the assay was ensured by the completeness of column separation and the selectivity of the antibodies used.’ Cross-reactivity of the p.G.F2IX antibody (supplied by J. Hennam) was: P.G.F2IX, 100; P.G.F,a, 62.5; P.G.E,, 6.6; and
p.G.A2,0.1. p.G.E2 radioimmunoassay
was performed in a manner almost indentical to that for p.G.F2IX but using 15 000 d.p.m. 3H-p.G.E2 and an antibody prepared against p.G.E2 (supplied by the Worcester Foundation) with cross-reactivity as follows:
p.G.E2, 100; P.G.EI2 128; p.G.A2, 1.8; P.G.F2IX, 1-6; p.G.B2, Separation of major P.G. metabolites was achieved by the chromatographic step. Blank values were always non-detectable (
