Platelet-activating factor acetylhydrolase activity in maternal, fetal, and newborn rabbit plasma during pregnancy and lactation.
Platelet-activating factor acetylhydrolase activity in maternal, fetal, and newborn rabbit plasma during pregnancy and lactation.
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妊娠和哺乳期间母体、胎儿和新生兔血浆中的血小板激活因子乙酰水解酶活性。
DOI：
10.1073/pnas.85.3.728
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发表时间：
1988
影响因子：
11.1
通讯作者：
Johnston,JM
中科院分区：
文献类型：
--
作者：
Maki,N;Hoffman,DR;Johnston,JM
生物活性含醚甘油磷脂血小板活化因子（PAF）的失活由PAF乙酰水解酶（1-烷基-2-乙酰基-sn-甘油-3-磷酸胆碱乙酰水解酶，EC 3.1.1.48）催化。乙酰水解酶的比活性已在母兔血浆中测定之前和整个怀孕和分娩后。非妊娠家兔血浆中乙酰水解酶的比活性为131 +/- 8 nmol.min-1.ml-1（平均值+/- SEM）。类似的具体活动，发现在整个怀孕的前半期，然而，在第15天的乙酰水解酶活性开始下降，并在第27天左右达到最低值。在分娩后24-48小时内，酶的比活性增加到非妊娠动物中发现的水平。胎儿（胎龄21-30天）和新生儿的乙酰水解酶比活性从血浆（21天）的22 nmol.min-1.ml-1增加到血浆（35天）的328 nmol.min-1.ml-1。妊娠兔血浆酶活性降低不能通过非妊娠和妊娠（27天）血浆混合实验测定的抑制剂的存在来解释。这种酶在家兔体内的特性与其他人报道的一致，即，底物特异性，热灭活和各种抑制剂，和Ca 2+的独立性。PAF乙酰水解酶的活性主要与兔血浆中的高密度脂蛋白组分有关。妊娠期间这种酶活性的降低可能有助于消除对子宫肌层的保护作用，从而使PAF的量增加，从而与该组织接触。
The inactivation of the biologically active ether-containing glycerophospholipid platelet-activating factor (PAF) is catalyzed by the enzyme PAF acetylhydrolase (1-alkyl-2-acetyl-sn-glycero-3-phosphocholine acetylhydrolase, EC 3.1.1.48). The specific activity of acetylhydrolase has been assayed in maternal rabbit plasma prior to and throughout pregnancy and after parturition. The specific activity of acetylhydrolase was 131 +/- 8 nmol.min-1.ml-1 of plasma (mean +/- SEM) in the nonpregnant rabbit. Similar specific activities were found throughout the first half of pregnancy; however, on day 15 the acetylhydrolase activity began to decrease and reached a minimum around day 27. Within 24-48 hr following delivery, the specific activity of the enzyme increased to the levels found in the nonpregnant animals. The specific activity of acetylhydrolase in fetuses (gestational ages of 21-30 days) and neonates increased from 22 nmol.min-1.ml-1 of plasma (21-day-old) to 328 nmol.min-1.ml-1 of plasma (35-day-old rabbits). The decrease in enzymatic activity of the pregnant rabbit plasma cannot be accounted for by the presence of an inhibitor as determined by plasma-mixing experiments with nonpregnant and pregnant (27-day) plasma. The properties of this enzyme in the rabbit were consistent with those reported by others, i.e., substrate specificity, inactivation by heat and various inhibitors, and Ca2+ independency. The activity of PAF acetylhydrolase was associated primarily with the high density lipoprotein fraction in rabbit plasma. The decrease of this enzymatic activity during pregnancy may serve to remove the protective effect on myometrium to allow an increased amount of PAF to come in contact with this tissue.
DOI：
--
发表时间：
1985
期刊：
影响因子：
--
作者：
J. Kuo
通讯作者：
J. Kuo