Houben H, Denef C
University of Leuven, School of Medicine, Department of Pharmacology, Belgium.
Peptides. 1994;15(3):547-82. doi: 10.1016/0196-9781(94)90218-6.
The anterior pituitary (AP) has been shown to contain a wide variety of bioactive peptides: brain-gut peptides, growth factors, hypothalamic releasing factors, posterior lobe peptides, opioids, and various other peptides. The localization of most of these peptides was first established by immunocytochemical methods and some of the peptides were localized in identified cell types. Although intracellular localization of a peptide may be the consequence of internalization from the plasma compartment, there is evidence for local synthesis of most of these peptides in the AP based on the identification of their messenger-RNA (mRNA). In several cases the release of the peptide from the AP cell has been shown and regulation of synthesis, storage and release have also been described. Because the amount of most of the AP peptides is very low (except for POMC peptides and galanin), endocrine functions are not expected. There is more evidence for paracrine, autocrine, or intracrine roles in growth, differentiation, and regeneration, or in the control of hormone release. To demonstrate such functions, in vitro AP experiments have been designed to avoid the interference of hypothalamic or peripheral hormones. The strategy is first to show a direct effect of the peptide after adding it to the in vitro system and, secondly, to explore if the endogenous AP peptide has a similar action by using blockers of peptide receptors or antisera immunoneutralizing the peptide.
垂体前叶（AP）已被证明含有多种生物活性肽：脑肠肽、生长因子、下丘脑释放因子、后叶肽、阿片类物质以及各种其他肽。这些肽中的大多数最初是通过免疫细胞化学方法确定其定位的，并且其中一些肽定位在已确定的细胞类型中。尽管肽的细胞内定位可能是从血浆区室内化的结果，但基于信使核糖核酸（mRNA）的鉴定，有证据表明这些肽中的大多数在垂体前叶中是局部合成的。在一些情况下，已证明肽从垂体前叶细胞中释放，并且也描述了其合成、储存和释放的调节。由于大多数垂体前叶肽的含量非常低（除了促黑素细胞激素原肽和甘丙肽），因此预期其不具有内分泌功能。有更多证据表明其在生长、分化和再生或激素释放控制中具有旁分泌、自分泌或胞内分泌作用。为了证明这些功能，已设计了体外垂体前叶实验以避免下丘脑或外周激素的干扰。策略首先是在将肽添加到体外系统后显示其直接作用，其次是通过使用肽受体阻滞剂或免疫中和该肽的抗血清来探索内源性垂体前叶肽是否具有类似作用。
