CONTROL OF PROLACTIN SECRETION
CONTROL OF PROLACTIN SECRETION
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DOI：
10.1007/bf01815271
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发表时间：
1990-12-04
期刊：
影响因子：
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通讯作者：
REINWEIN, D
中科院分区：
文献类型：
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作者：
BENKER, G;JASPERS, C;REINWEIN, D
1.催乳素是一种21，500道尔顿的单链多肽激素，但可能以50 kDa和150 kDa的分子变体存在。2.这些大的PRL变体可能主要分泌;这种情况被称为“巨催乳素血症”。其特点是血清中泌乳素的免疫学和生物学水平均较高，且无高泌乳素血症的临床症状。3. PRL的信息编码在6号染色体上。转录可以被多种激素因子增强和抑制。4. PRL以脉动的方式分泌;它显示昼夜节律（在睡眠期间达到最大值），并受到某些氨基酸的刺激。催乳素也对乳房的机械刺激有反应。5.催乳素在怀孕期间升高，高催乳素血症（从而导致生理性不孕）的发生依赖于母乳喂养的频率和持续时间。下丘脑中存在的各种刺激因子的生理重要性仍然不完全清楚。特别是，在催乳素生理学中仍然没有TRH的位置。7.催乳素在应激反应中释放;这种反应可能由阿片类药物介导。然而，低雌激素、低促性腺激素的闭经并不是由催乳素介导的。8.雌激素通过至少两种独立的机制刺激PRL基因转录。临床上有许多例子表明雌激素对血清催乳素水平以及催乳素瘤的生长有影响。9.轻度高催乳素血症仍然是一个谜，不能通过生物化学或放射学检测满意地解决。催乳素“正常”和“升高”之间的界限是不明确的。大量催乳素血症的可能性使这一问题更加复杂。10.通过作用于垂体D2受体来抑制催乳素的药物以及用于治疗高催乳素血症的药物的数量继续增加。在麦角生物碱领域，胃肠外给药似乎是解决首过效应高问题的合理方案;此外，这种治疗形式通常比口服途径耐受性更好。11.目前正在利用分子生物学技术研究泌乳素瘤的发展;肿瘤发生是否可归因于基因调控的特定缺陷的问题仍有待回答。
1.Prolactin is a 21,500 Dalton single-chain polypeptide hormone but may occur in 50 kDa and 150 kDa molecular variants.2.These large PRL variants may be secreted predominantly; this condition is termed “macroprolactinemia”. It is characterized by high immunological and normal biological serum levels of prolactin, and lack of clinical symptoms of hyperprolactinemia.3.The information on PRL is encoded on chromosome 6. Transcription can be enhanced and suppressed by a variety of hormonal factors.4.PRL is secreted in a pulsatile fashion; it displays a circadian rhythm (with a maximum during sleep) and is stimulated by some amino acids. PRL also responds to mechanical stimulation of the breast.5.PRL rises during pregnancy, and maintainance of hyperprolactinemia (and, thereby, physiological infertility) is dependent on the frequency and duration of breast feedings.6.Hypothalamic regulation of prolactin mainly involves tonic inhibition via portal dopamine. The physiological importance of various stimulating factors present in the hypothalamus is still incompletely understood. In particular, there is still no place for TRH in PRL physiology.7.PRL is released in response to stress; this response may be mediated by opioids. The low-estrogen, low-gonadotropin amenorrhea of endurancetraining women is not mediated by prolactin, however.8.Estrogens stimulate PRL gene transcription via at least two independent mechanisms. There are many clinical examples of this estrogen effect on prolactin serum levels, and also on the growth of prolactinomas.9.Mild hyperprolactinemia remains an enigma which cannot satisfactorily be resolved by biochemical or radiological testing. The border between “normal” and “elevated” prolactin is illdefined. The possibility of macroprolactinemia complicates this matter even further.10.The number of drugs which suppress prolactin by acting on pituitary D2receptors, and which are useful in the treatment of hyperprolactinemia, continues to increase. In the field of ergot alkaloids, parenteral application appears to be a logical solution to the problem of the high first-pass effect; in addition, this form of treatment is frequently better tolerated than the oral route.11.Prolactinoma development is presently being studied employing molecular biological techniques; the question of whether tumorigenesis can be attributed to specific defects of gene regulation remains to be answered.