Hirshfield A N
Department of Anatomy, University of Maryland, School of Medicine, Baltimore 21201.
Biol Reprod. 1991 Jun;44(6):1157-62. doi: 10.1095/biolreprod44.6.1157.
Opinions differ concerning when theca cells arise during follicular growth. Theca cells cannot be distinguished from ovarian stroma cells on the basis of morphology alone. However, long-term continuous infusion of [3]thymidine (3H-TdR) thoroughly labels theca cells of large and medium-sized follicles whereas most stromal cells remain unlabeled. The objective of this study was to determine when, during the course of follicular development, labeled, squamous cells located just outside the follicular basement membrane (putative theca cells) first become apparent. Rats were given infusions of 3H-TdR for various periods of time. Autoradiographs were prepared from 2-microns-thick plastic sections of ovaries. Morphologically recognizable theca cells of large and medium-sized follicles were sharply delineated from surrounding stroma cells by their labeling pattern. Although unilaminar follicles lacked morphologically distinct theca layers, they all were closely enveloped by labeled cells just outside the basement membrane. Follicles with a few as 4-5 granulosa cells in cross section often had labeled cells on the convex surface of their basement membranes. These observations suggest the possibility that theca cells may already be present at the very outset of follicular growth.
关于卵泡生长过程中膜细胞何时出现，存在不同观点。仅根据形态学无法将膜细胞与卵巢基质细胞区分开来。然而，长期持续输注[3]胸腺嘧啶核苷（3H-TdR）可彻底标记大中型卵泡的膜细胞，而大多数基质细胞仍未被标记。本研究的目的是确定在卵泡发育过程中，位于卵泡基底膜外侧的被标记的扁平细胞（推测为膜细胞）首次出现的时间。给大鼠输注3H-TdR不同时间段。从卵巢2微米厚的塑料切片制备放射自显影片。大中型卵泡形态上可识别的膜细胞通过其标记模式与周围基质细胞清晰区分。尽管单层卵泡缺乏形态上明显的膜层，但它们都被基底膜外侧的标记细胞紧密包裹。横切面上仅有4-5个颗粒细胞的卵泡，其基底膜凸面常有标记细胞。这些观察结果提示，在卵泡生长一开始可能就已存在膜细胞。
