著者

野口 有生 平戸 久美子 斉藤 裕 高崎 克哲 矢内原 巧 中山 徹也 Yusei NOGUCHI Kumiko HIRATO Hiroshi SAITO Katsunori TAKASAKI Takumi YANAIHARA Tetsuya NAKAYAMA 昭和大学医学部産科婦人科学教室 昭和大学医学部産科婦人科学教室 昭和大学医学部産科婦人科学教室 昭和大学医学部産科婦人科学教室 昭和大学医学部産科婦人科学教室 昭和大学医学部産科婦人科学教室 Department of Obstetrics and Gynecology Showa University School of Medicine Department of Obstetrics and Gynecology Showa University School of Medicine Department of Obstetrics and Gynecology Showa University School of Medicine Department of Obstetrics and Gynecology Showa University School of Medicine Department of Obstetrics and Gynecology Showa University School of Medicine Department of Obstetrics and Gynecology Showa University School of Medicine

雑誌

日本産科婦人科學會雜誌 = Acta obstetrica et gynaecologica Japonica (ISSN:03009165)

巻号頁・発行日

vol.40, no.3, pp.359-364, 1988-03-01

被引用文献数

1

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分娩時ヒト子宮頚部組織における遊離アラキドン酸生成能と, それに及ぼす妊娠性ステロイドの影響を調べる目的で次の実験を行ない, 以下の成績を得た. 1) 正常分娩のヒト子宮頚部組織800g上清を酵素源とし, L-3-phosphatidylcholine, 1-stearoyl-2-[1-^<14>C]arachidonylを基質とし, インキュベーションを行ない, 遊離されたアラキドン酸産生量よりphospholipase A_2活性を測定し, 更に各種のkineticsを行ない, ヒト子宮頚部組織内でリン脂質より遊離アラキドン酸産生に介在するphospholipase A_2活性が存在することを示した. 2) 培養液中に妊娠中増加する各種の妊娠性ステロイド(cortisol, pregnenolone, 20α-dihydroprogesterone, pregnenolone-sulfate, DHA, DHA-sulfate, estrone, estradiol, estriol)を添加し, 本酵素活性に及ぼす影響を検討した. 各種妊娠性ステロイド添加では, 本酵素活性に対し, 明らかに影響を示すものはなかつた. 3) 分娩第1期に母体にDHA-sulfate (マイリス) 600mgを2時間で点滴静注した後, 分娩に至つたDHA-sulfate投与群と非投与正常分娩例との本酵素活性の比較では, 投与群40±13pmoles/mg protein であり, 非投与正常分娩例の39±7pmoles/mg proteinと比し差はみられなかつた. 以上のことよりヒト妊娠子宮頚部に, phospholipase A_2活性が存在することが明らかとなり, また, 本実験条件下ではprostaglandin合成機構の一過程であるphospholipase A_2活性に対する妊娠性ステロイドの関与は認められなかつた.Prostaglandins (PGs) play an important role in cervical ripening. It is known that the hydrolytic release of arachidonic acid from phospholipids regulates the rate of PG formation. To study the PG biosynthesis in cervical tissue, phosphatidylcholine containing ^<14>C-arachidonic acid in Sn-2 position was incubated with the 800 × g supernatant of cervical tissue obtained from pregnant women at delivery. The only recognizable radiolabeled metabolite, ^<14>C-arachidonic acid, was found on an autor-adiogram of TLC, which corresponded to authentic arachidonic acid. Therefore, phospholipase A_2 activity was calculated as the rate of the release of arachidonic acid from phosphatidylcholine under the conditions used. The optimal pH of phospholipase A_2 activity in 800 × g supernatant was found to be 7.0. It was found that the addition of Ca^<2+> increased the enzyme activity. It was demonstrated that the concentrations of DHA-sulfate (DHA-S) and conjugated estrogens were higher in ripened cervical tissue than in non-ripened tissue and that PGI_2 and PGE_2 production increased following the addition of DHA-S. The effects of steroids mainly derived from feto-placental unit, cortisol, pregnenolone, 20α-dihydroprogesterone, pregnenolone-sulfate, DHA, DHA-S, estrone, estradiol and estriol on arachidonic acid release were also studied in vitro. After the onset of labor, DHA-S was administered to the patients in vivo and their cervical tissues were collected at delivery. It was found that steroids including DHA-S did not affect phospholipase A_2 activity under the conditions used. These results indicate that cervical tissue posseses the ability to release arachidonic acid from phospholipid, although this step in PG formation might not be affected by steroids including DHA-S.