- Email: [email protected]
Release of PGD2 as a major product from the isolated rat pregnant uterus
PROSTAGLANDINS
PLEASE OF PGJ2 AS A MAJOR PRODUCT FROM-W JlZ$RUS, M. Katori, Y. Harada, Y. Yamashita*, M. Ishibashi, and H. Miyazaki*, Dept. of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa and *Research Laboratory, Pharmaceutical Division, Nippon Kayaku Co., Ltd., Tokyo, Japan. ABSTRACT PGF2b has been believed to be a major product released from uterus. Uteri were removed from Wistar rats 20-21 days pregnant and suspended in 10 ml organ bath filled with Krebs solution at 37OC bubbled with 95% 02 and 5% C02. Prostaglandin (PG) released for over 30 min into the surrounding bath fluid were extracted and assayed by superfusion using a rat stomach strip and rat colon with Krebs solution containinu a mixture of antaaonists (Gilmore et al. 1968). The amount of PGE -like substance-was determined cfrom the response of the rat stoiach strip and that of PGF a-like with substance from the resoonse of the rat colon, in comoariso fli authentic PGE and PGF24 respectively (Harada et al.-1975). The amounts of bo $h PGs in the bath fluid increaserwxh time and reached the maximum at 1.5 hr: the ratio of PGF,h/PGE? was 2.5-3. Indomethacin (0.005-5 PM); phenylbutazone (ALSO yfi) or benzydamine (2-50 Thin layer ,oM) reduced the release of both PGs dose-dependently. 'chromatography of the extracts using the A-II solvent system (Green and Samuelsson, 1964), however, indicated that the major part of the activity was in the zone equivalent to PGFlEI, PGD and 6-ketoPGF b which have similar Rf values in the solvent sys 8em. The pos.&bility that 6-keto-PGFlq contributed substantially to the biological activity was excluded since up to 0.5 pg did not contract the rat colon, but PGD2 caused contraction (20 ng). Gas chromatography-mass spectrometry (GCMS) revealed the presence of PGD2, PGE and PGF2h in the extract from the bath fluid, but PGD and 6-keto2 PGFlU, were not detected. Quantitative analysis by GCR S showed that the ratio of PGD2/PGF2& was 1 to 2.6, so that PGD2 is a major product released from the rat isolated pregnent uterus. ELiE,~U~TION_AN1?._EGIT-,_~NNHIB_STION QF .A.RA_CHI.DONIC ACID AND' EEoST~l~~PRE-LABEL,D_FSBRQB.~sTS IN CULTURE, Sei-itsu Murota, Tokiya Yokoi and Yo Mori, Department of Pharmacology, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173, Japan. ABSTRACT PGF2h enhanced the release of radioactivity from 14C-arachidonic acid labeled fibroblasts. Thin layer chromatographic analysis of the radioactivity released from the cells indicated that 90% was due to 14C-arachidonic acid and the rest was due to 14C-PGE2 in both the PGF & and the control cultures. A dose-response experiment revealed tha z the threshold effect of PGF$ was 10 ng/ml and stimulation was maximal above 100 ng/ml. The effect of various prostaglandins and related compounds on the arachidonic acid release was
APRIL
1978 VOL. 15 NO. 4
697
PLEASE OF PGJ2 AS A MAJOR PRODUCT FROM-W JlZ$RUS, M. Katori, Y. Harada, Y. Yamashita*, M. Ishibashi, and H. Miyazaki*, Dept. of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa and *Research Laboratory, Pharmaceutical Division, Nippon Kayaku Co., Ltd., Tokyo, Japan. ABSTRACT PGF2b has been believed to be a major product released from uterus. Uteri were removed from Wistar rats 20-21 days pregnant and suspended in 10 ml organ bath filled with Krebs solution at 37OC bubbled with 95% 02 and 5% C02. Prostaglandin (PG) released for over 30 min into the surrounding bath fluid were extracted and assayed by superfusion using a rat stomach strip and rat colon with Krebs solution containinu a mixture of antaaonists (Gilmore et al. 1968). The amount of PGE -like substance-was determined cfrom the response of the rat stoiach strip and that of PGF a-like with substance from the resoonse of the rat colon, in comoariso fli authentic PGE and PGF24 respectively (Harada et al.-1975). The amounts of bo $h PGs in the bath fluid increaserwxh time and reached the maximum at 1.5 hr: the ratio of PGF,h/PGE? was 2.5-3. Indomethacin (0.005-5 PM); phenylbutazone (ALSO yfi) or benzydamine (2-50 Thin layer ,oM) reduced the release of both PGs dose-dependently. 'chromatography of the extracts using the A-II solvent system (Green and Samuelsson, 1964), however, indicated that the major part of the activity was in the zone equivalent to PGFlEI, PGD and 6-ketoPGF b which have similar Rf values in the solvent sys 8em. The pos.&bility that 6-keto-PGFlq contributed substantially to the biological activity was excluded since up to 0.5 pg did not contract the rat colon, but PGD2 caused contraction (20 ng). Gas chromatography-mass spectrometry (GCMS) revealed the presence of PGD2, PGE and PGF2h in the extract from the bath fluid, but PGD and 6-keto2 PGFlU, were not detected. Quantitative analysis by GCR S showed that the ratio of PGD2/PGF2& was 1 to 2.6, so that PGD2 is a major product released from the rat isolated pregnent uterus. ELiE,~U~TION_AN1?._EGIT-,_~NNHIB_STION QF .A.RA_CHI.DONIC ACID AND' EEoST~l~~PRE-LABEL,D_FSBRQB.~sTS IN CULTURE, Sei-itsu Murota, Tokiya Yokoi and Yo Mori, Department of Pharmacology, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173, Japan. ABSTRACT PGF2h enhanced the release of radioactivity from 14C-arachidonic acid labeled fibroblasts. Thin layer chromatographic analysis of the radioactivity released from the cells indicated that 90% was due to 14C-arachidonic acid and the rest was due to 14C-PGE2 in both the PGF & and the control cultures. A dose-response experiment revealed tha z the threshold effect of PGF$ was 10 ng/ml and stimulation was maximal above 100 ng/ml. The effect of various prostaglandins and related compounds on the arachidonic acid release was
APRIL
1978 VOL. 15 NO. 4
697