摘要
作者报道胰岛素样生长因子－Ⅰ（ＩＧＦ－Ⅰ）ｍＲＮＡ在大鼠睾丸中的基因表达。用１５％～６０％Ｐｅｒｃｏｌｌ密度梯度离心，可将粗制间质细胞分成三条带，ＩＧＦ－ⅠｍＲＮＡ主要位于富含Ｌｅｙｄｉｇ细胞的组分（带３）中，带１和带２组分几乎不含ＩＧＦ－ⅠｍＲＮＡ。Ｌｅｙｄｉｇ细胞ＩＧＦ－ⅠｍＲＮＡ具有碱基从０．８～７．５ｋｂ的多种型，在２５～５５日龄大鼠中均存在ＩＧＦ－ⅠｍＲＮＡ，用Ｋｌｉｎｅｆｅｌｔｅｒ等方法高度纯化Ｌｅｙｄｉｇ细胞，发现大多数ＩＧＦ－ⅠｍＲＮＡｆｔ于这些Ｌｅｙｄｉｇ细胞中，而在整个睾丸组织或其它间质细胞检测不到ＩＧＦ－ⅠｍＲＮＡ。大鼠予以生长激素（ＧＨ）后，Ｌｅｙｄｉｇ细胞中ＩＧＦ－ⅠｍＲＮＡ增加２倍以上，提示Ｌｅｙｄｉｇ细胞中的ＩＧＦ－ⅠｍＲＮＡ亦依赖ＧＨ，Ｌｅｙｄｉｇ细胞产生的ＩＧＦ－Ⅰ在睾丸中可能具有自分泌和旁分泌作用。
In the present study, the authors evaluated the mRNA expression of insulin-like growth factor-Ⅰ(IGF-Ⅰ) in rat testis. Interstitial cells were separated into three distinct bands through 15%-60% Percoll density gradient centrafugation. IGF-Ⅰ mRNA was mainly located in the Leydig cell-enriched fraction (band 3), while cells in band 1 and band 2 did not contain significant amounts of IGF-Ⅰ mRNA. Leydig cell IGF-ⅠmRNA consiusted of multiple species varying from 0.8 to 7.5 kb and was present in rats of 25 to 55 days of age. The method by Klinefel ter et al was adopted to isolate the highly purified Leydig cells. Most of the IGF-ⅠmRNA was detected in these Leydig cells, but no detectable IGF-ⅠmRNA was seen in the whole testis or other interstitial cells. Furthermore, IGF-ⅠmRNA in Leydig cells increased more than 2-fold by growth hormone (GH)administration in vivo. This suggests that IGF-ⅠmRNA in Leydig cells is also GH dependent. Interstitial IGF-Ⅰproduced in Leydig cells may have both autocrine and paracrine effects on the testis.
