Byrne J M, Jones P M, Hill S F, Bennet W M, Ghatei M A, Bloom S R
Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.
J Clin Endocrinol Metab. 1992 Oct;75(4):983-7. doi: 10.1210/jcem.75.4.1383256.
The local production of autocrine or paracrine agents in endocrine tissues represents an important level of hormonal regulation. The synthesis of neuropeptide-Y (NPY), substance-P (SP), and vasoactive intestinal peptide (VIP) in the rat anterior pituitary gland has been well demonstrated. We have now studied their expression in human postmortem pituitary tissue. Northern blot analysis of poly(A)+ RNA from whole human pituitaries revealed mRNA encoding the precursors for NPY, SP, and VIP whose hybridization characteristics were indistinguishable from those of the same mRNAs described in previously characterized human tissues. VIP mRNA was detectable in all samples tested, with NPY and preprotachykinin-A mRNA (which encodes SP) detectable in a subset of the pituitaries. The concentration of immunoreactive NPY in whole human pituitary was 3.8 +/- 1.1 pmol/g wet wt in males and 2.9 +/- 0.5 pmol/g wet wt in females (mean +/- SEM; n = 10), that of SP was 3.1 +/- 0.4 pmol/g wet wt in males and 5.2 +/- 1.3 pmol/g wet wt in females (n = 10), and that of VIP was 8.1 +/- 2.9 pmol/g wet wt in males and 5.3 +/- 1.6 pmol/g wet wt in females (n = 10). Size-fractionation of pituitary extracts by gel permeation chromatography revealed single peaks of NPY and VIP-like immunoreactivity in the positions of the standards, while SP-like immunoreactivity mostly eluted in the position of synthetic SP, with two minor immunoreactive peaks eluting earlier. The low levels of NPY, SP, and VIP and their mRNAs in the human pituitary are consistent with peptides having an autocrine/paracrine, rather than endocrine, mode of action.
内分泌组织中自分泌或旁分泌因子的局部产生代表了激素调节的一个重要层面。大鼠垂体前叶中神经肽Y（NPY）、P物质（SP）和血管活性肠肽（VIP）的合成已得到充分证实。我们现在研究了它们在人类尸检垂体组织中的表达。对整个人类垂体的聚腺苷酸加尾RNA（poly(A)+ RNA）进行Northern印迹分析，发现了编码NPY、SP和VIP前体的mRNA，其杂交特征与先前已鉴定的人类组织中相同mRNA的特征无法区分。在所有测试样本中均可检测到VIP mRNA，而在一部分垂体中可检测到NPY和前速激肽原A mRNA（编码SP）。男性整个人类垂体中免疫反应性NPY的浓度为3.8±1.1 pmol/g湿重，女性为2.9±0.5 pmol/g湿重（平均值±标准误；n = 10）；SP的浓度男性为3.1±0.4 pmol/g湿重，女性为5.2±1.3 pmol/g湿重（n = 10）；VIP的浓度男性为8.1±2.9 pmol/g湿重，女性为5.3±1.6 pmol/g湿重（n = 10）。通过凝胶渗透色谱法对垂体提取物进行大小分级分离，结果显示NPY和VIP样免疫反应性在标准品位置出现单峰，而SP样免疫反应性大多在合成SP的位置洗脱，还有两个较小的免疫反应性峰洗脱较早。人类垂体中NPY、SP和VIP及其mRNA的低水平与这些肽具有自分泌/旁分泌而非内分泌作用模式一致。
