Release of pituitary growth hormone by prostaglandins and dibutyryl adenosine cyclic 3':5'-monophosphate in the absence of protein synthesis.
Release of pituitary growth hormone by prostaglandins and dibutyryl adenosine cyclic 3':5'-monophosphate in the absence of protein synthesis.
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在没有蛋白质合成的情况下，前列腺素和二丁酰腺苷环 3:5-单磷酸释放垂体生长激素。
DOI：
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发表时间：
1970
影响因子：
11.1
通讯作者：
J. Lehmeyer
中科院分区：
文献类型：
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作者：
R. Macleod;J. Lehmeyer
研究了前列腺素对[4，5-(3)H]亮氨酸掺入生长激素及其随后释放到培养液中的影响。大鼠垂体前叶与10(-6)M前列腺素PGE(1)在组织培养液199中孵育7小时，可使标记生长激素释放到孵育液中增加40-300%。PGE(1)在10(-8)M时促进生长激素的合成，但不促进生长激素的释放。在10(-6)M时，PGE(2)的作用与PGE(1)相似，PGA(1)促进生长激素的合成，但不促进生长激素的释放。PGF(2α)对生长激素的合成和释放均无影响，催乳素的合成和释放也不受前列腺素的影响。在10(-4)M时，所有前列腺素均能增加脑垂体腺苷酸环化酶的活性，但不改变磷酸二酯酶的活性。无论有没有咖啡因，二丁酰环AMP都能使标记的生长激素释放增加高达300%。未观察到催乳素的持续作用。如果钾浓度增加10倍，生长激素释放增加215%。高渗钾和10(-6)M前列腺素E(1)的组合使生长激素释放增加325%，表明钾和前列腺素是通过独立的机制起作用的。在体外培养的脑下垂体中加入茶碱，可促进生长激素的合成和释放。虽然氟化物极大地促进了生长激素的释放，但它完全抑制了亮氨酸进入激素。同样，嘌呤霉素抑制生长激素的合成，但不能阻止前列腺素、二丁酰环AMP、茶碱或氟化物诱导的释放。前列腺素可增加垂体腺苷环化酶的活性，并可能通过环腺苷酸增加生长激素的释放，而不依赖于蛋白质的合成。
Effects of prostaglandins on the incorporation of [4,5-(3)H]leucine into growth hormone and its subsequent release into the incubation medium were studied. Incubation of rat anterior pituitary glands with 10(-6) M prostaglandin PGE(1) in tissue culture medium 199 for 7 hr caused a 40-300% increase in the release of labeled growth hormone into the incubation medium. PGE(1) at 10(-8) M increased growth hormone synthesis but not release. At 10(-6) M, PGE(2) had effects similar to PGE(1); PGA(1) increased growth hormone synthesis but not release. PGF(2alpha) was without effect on either synthesis or release of growth hormone.Prolactin synthesis and release were not affected by prostaglandins. All of the prostaglandins, at 10(-4) M, increased adenyl cyclase activity in the pituitary gland but phosphodiesterase activity was unaltered. Dibutyryl cyclic AMP, with or without caffeine, caused an up to 300% increase in labeled growth hormone release. No consistent effect of prolactin was observed. If potassium concentration was increased 10-fold, a 215% increase in growth hormone release was observed. A combination of hypertonic potassium and 10(-6) M PGE(1) increased growth hormone release 325%, suggesting that potassium and prostaglandins act by independent mechanisms. Addition of theophylline to pituitary gland, incubated in vitro, increased both the synthesis and release of growth hormone. Although fluoride greatly stimulated growth hormone release, it completely inhibited the incorporation of leucine into the hormone. Similarly, puromycin inhibited synthesis of growth hormone but did not block release induced by prostaglandin, dibutyryl cyclic AMP, theophylline, or fluoride. Prostaglandins increase pituitary adenyl cyclase activity and, presumably via cyclic AMP, increase growth hormone release, independently of protein synthesis.