Skinner M K, Lobb D, Dorrington J H
Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee.
Endocrinology. 1987 Nov;121(5):1892-9. doi: 10.1210/endo-121-5-1892.
An ovarian thecal/interstitial cell preparation was obtained by enzymatic digestion of immature rat ovaries depleted of granulosa cells. A component in thecal/interstitial cell-conditioned medium inhibited specific binding of [125I]iodo-epidermal growth factor ([125I]EGF) to its cell surface receptor, as determined with an EGF radioreceptor assay. Thecal/interstitial cell secreted proteins also stimulated growth of an EGF-dependent cell line. Granulosa cells isolated from the same ovaries did not produce detectable levels of an EGF-like substance, as determined by both EGF RRA and EGF growth assay. Fractionation of thecal/interstitial cell secreted proteins by size exclusion HPLC resulted in a 35K component being detected by both the EGF RRA and the growth assay. An EGF-like substance was also detected when thecal/interstitial cell secreted proteins were fractionated by reverse phase HPLC. Several biochemical properties of the EGF-like substance examined were different from those of authentic mouse EGF. However, the biological activities of the EGF-like substance and mouse EGF were similar in their ability to promote the growth of an EGF-dependent cell line. In addition to the production of an EGF-like substance, the thecal/interstitial cell preparation also produced an EGF inhibitory activity. This thecal/interstitial cell secreted product was fractionated from the EGF-like substance and inhibited the ability of EGF to stimulate cell growth. EGF receptors are present on granulosa cells, and EGF is known to influence both the growth and differentiation of these cells. Observations indicate that ovarian thecal/interstitial cells produce an EGF-like substance that may act as a paracrine factor to regulate granulosa cell growth and differentiation. In addition, an EGF inhibitory activity is produced that also may have a role in regulating follicular cell growth.
通过酶消化去除颗粒细胞的未成熟大鼠卵巢，获得卵巢膜细胞/间质细胞制剂。用表皮生长因子（EGF）放射受体分析法测定，膜细胞/间质细胞条件培养基中的一种成分可抑制[125I]碘-表皮生长因子（[125I]EGF）与其细胞表面受体的特异性结合。膜细胞/间质细胞分泌的蛋白质也能刺激依赖EGF的细胞系生长。通过EGF放射受体分析法和EGF生长试验测定，从同一卵巢分离的颗粒细胞未产生可检测水平的类EGF物质。通过尺寸排阻高效液相色谱法对膜细胞/间质细胞分泌的蛋白质进行分级分离，结果显示在EGF放射受体分析法和生长试验中均检测到一种35K的成分。当通过反相高效液相色谱法对膜细胞/间质细胞分泌的蛋白质进行分级分离时，也检测到一种类EGF物质。所检测的类EGF物质的几种生化特性与天然小鼠EGF不同。然而，类EGF物质和小鼠EGF在促进依赖EGF的细胞系生长的能力方面具有相似的生物学活性。除了产生类EGF物质外，膜细胞/间质细胞制剂还产生一种EGF抑制活性。这种膜细胞/间质细胞分泌产物与类EGF物质分离，并抑制EGF刺激细胞生长的能力。颗粒细胞上存在EGF受体，已知EGF会影响这些细胞的生长和分化。观察结果表明，卵巢膜细胞/间质细胞产生一种类EGF物质，可能作为旁分泌因子调节颗粒细胞的生长和分化。此外，还产生一种EGF抑制活性，其也可能在调节卵泡细胞生长中发挥作用。
