Chiwakata C, Brackmann B, Hunt N, Davidoff M, Schulze W, Ivell R
Institute for Hormone and Fertility Research, Hamburg, Germany.
Endocrinology. 1991 May;128(5):2441-8. doi: 10.1210/endo-128-5-2441.
Specific substance-P immunoreactivity can be detected in the Leydig cells, particularly of human testes, and to a lesser degree in mouse Leydig cells, but not in the rat. Using a modified polymerase chain reaction (PCR) assay, preprotachykinin-A (substance-P) mRNA could be detected in extracts of human, mouse, and bovine testes, but not in rat or boar testes or in bovine thyroid or corpus luteum used as negative controls. This assay is able to discriminate among the alpha, beta, and gamma transcripts of the gene and shows that only the beta and gamma transcripts are present in the testes. Sequencing analysis of the PCR products from bovine hypothalamus, mouse brain, and human testis confirmed the structure of these transcripts, which encode both substance-P and neurokinin-A (substance-K) neuropeptide hormones. Using a variant of this assay it was possible to identify tachykinin transcripts in as few as 500 freshly prepared purified mouse Leydig cells. In parallel studies PCR analysis was also able to confirm the presence of mRNA for both substance-P and neurokinin-A receptors in human testes. Thus, the tachykinins substance-P and neurokinin-A must now be added to the list of potentially paracrine substances regulating intratesticular function.
在间质细胞中可检测到特异性P物质免疫反应性，尤其是在人类睾丸的间质细胞中，在小鼠间质细胞中的程度较低，但在大鼠中则未检测到。使用改良的聚合酶链反应（PCR）检测法，可在人类、小鼠和牛的睾丸提取物中检测到前速激肽原A（P物质）mRNA，但在大鼠或公猪睾丸以及用作阴性对照的牛甲状腺或黄体中未检测到。该检测法能够区分该基因的α、β和γ转录本，并表明睾丸中仅存在β和γ转录本。对来自牛下丘脑、小鼠脑和人类睾丸的PCR产物进行测序分析，证实了这些转录本的结构，它们编码P物质和神经激肽A（物质K）神经肽激素。使用该检测法的一种变体，能够在仅500个新鲜制备的纯化小鼠间质细胞中鉴定速激肽转录本。在平行研究中，PCR分析也能够证实在人类睾丸中存在P物质和神经激肽A受体的mRNA。因此，速激肽P物质和神经激肽A现在必须被添加到调节睾丸内功能的潜在旁分泌物质列表中。
