Kobayashi J, Mizunuma H, Kikuchi N, Liu X, Andoh K, Abe Y, Yokota H, Yamada K, Ibuki Y, Hagiwara H
Department of Obstetrics and Gynecology, 1st Department of Anatomy, Gunma University School of Medicine, Maebashi, Gunma, 371-8511, Japan.
Biochem Biophys Res Commun. 2000 Feb 5;268(1):36-41. doi: 10.1006/bbrc.1999.2072.
The present study was carried out to verify that the cells attached to the outside of the basement membrane of mechanically isolated follicles are theca cells and to evaluate the effect of growth hormone (GH) on these cells. Preantral follicles, 100-140 micrometer in diameter, were mechanically isolated from 11-day-old BDF1 hybrid immature mice, divided randomly into two groups, and cultured in vitro. One group was treated with 0.1% collagenase immediately after mechanical isolation in an attempt to remove theca cells attached to the outside of the basement membrane. The other group was untreated. Morphological examination revealed that 86.1% of mechanically isolated follicles before collagenase treatment had at least one theca cell around the basement membrane on the single section. However, after collagenase treatment no theca cells remained on the basement membrane of the follicles. Androstenedione secretion as a result of stimulation by 100 ng/ml hCG was significantly higher in the culture medium of the follicles with theca cells than in those of collagenase-pretreated follicles (p < 0.0001), indicating that the cells attached to the outside of the basement membrane were actually functional theca cells, not interstitial cells. To elucidate the effect of GH on theca cells, preantral follicles cultured in the presence of 1.0 mIU/ml GH were morphologically examined. Preantral follicles mechanically isolated from immature mice showed significant proliferation of not only granulosa cells but also theca cells in the presence of GH. In particular, theca cells, which remained dotted on the basement membrane in a small number just after isolation, proliferated and finally formed complete layers after the culture with GH. This is the first report that GH induced the proliferation of theca cells to form morphologically complete layers around the preantral follicle from 11-day-old mice.
本研究旨在验证机械分离卵泡基底膜外侧附着的细胞是否为卵泡膜细胞，并评估生长激素（GH）对这些细胞的影响。从11日龄的BDF1杂交未成熟小鼠中机械分离出直径为100 - 140微米的窦前卵泡，随机分为两组并进行体外培养。一组在机械分离后立即用0.1%胶原酶处理，试图去除附着在基底膜外侧的卵泡膜细胞。另一组未处理。形态学检查显示，在胶原酶处理前，86.1%的机械分离卵泡在单个切片的基底膜周围至少有一个卵泡膜细胞。然而，胶原酶处理后，卵泡基底膜上没有卵泡膜细胞残留。100 ng/ml人绒毛膜促性腺激素（hCG）刺激后，有卵泡膜细胞的卵泡培养基中雄烯二酮分泌显著高于胶原酶预处理卵泡的培养基（p < 0.0001），表明附着在基底膜外侧的细胞实际上是功能性卵泡膜细胞，而非间质细胞。为阐明GH对卵泡膜细胞的影响，对在1.0 mIU/ml GH存在下培养的窦前卵泡进行形态学检查。从未成熟小鼠机械分离的窦前卵泡在GH存在下不仅颗粒细胞显著增殖，卵泡膜细胞也显著增殖。特别是，刚分离时少量点状分布在基底膜上的卵泡膜细胞，在GH培养后增殖并最终形成完整的层。这是首次报道GH诱导11日龄小鼠窦前卵泡周围的卵泡膜细胞增殖并形成形态完整的层。
