Inkster S E, Brodie A M
Dept. Pharmacology and Experimental Therapeutics University of Maryland, School of Medicine, Baltimore 21201.
J Clin Endocrinol Metab. 1991 Oct;73(4):717-26. doi: 10.1210/jcem-73-4-717.
The cellular distribution of the aromatase cytochrome P-450 enzyme in human ovaries has been investigated immunocytochemically, using an aromatase-specific monoclonal antibody. Ovaries of females ranging in age from prepubertal infant girl through to postmenopausal adulthood were obtained from immediate autopsy or after surgery. The results have revealed temporal and spatial changes in expression of aromatase at different stages of development. No immunoreactive aromatase was detected in the ovary of the 2.5 month infant. In premenopausal ovaries, aromatase was absent from the stromal compartment, but in follicles, a consistent pattern in expression of aromatase was observed, related to their size and developmental stage. Aromatase was not expressed in primordial, primary, or small secondary follicles less than 250 microns diameter. In slightly larger follicles (250-700 microns diameter) aromatase was first detected in a few thecal cells (TC). In more developed secondary through to large preovulatory follicles (greater than 1 cm) TC aromatase immunostain increased in intensity and number of positive cells, and the reaction was localized to a band of theca interna (TI) cells at the TI/theca externa interface. In granulosa cells (GC), aromatase was first detected in follicles in the initial stages of antrum formation (greater than 700 microns), and staining intensified as follicle diameter and antral cavity increased, being maximal in preovulatory follicles. GC aromatase was always found in the presence of TI immunostain. These two cell populations were separated by an unstained layer of TI cells giving the follicle walls a banded appearance. Immunostain was most intense in mural GC, was weaker in antral GC cells and was absent from the cumulus GC. Immunoreactive aromatase was also detected in functional corpora lutea (CL) but was absent from involuting CL's and corpora albicans. Our findings indicate that the immunostained cells of the CL are comprised of the former GC and possibly a subpopulation of former TI cells. In perimenopausal ovaries there was no evidence of any follicular or stromal aromatase immunostain. In postmenopausal ovaries no follicles were observed, but individual cells and clusters of cells in the stromal compartment of 3/7 specimens were found to have an aromatase immunostain reaction. In all cases, the aromatase immunostain reaction was cytoplasmic. The results provide the first direct evidence of the existence of TC aromatase, and of stromal cell aromatase in postmenopausal women.
利用芳香化酶特异性单克隆抗体，通过免疫细胞化学方法研究了芳香化酶细胞色素P - 450酶在人卵巢中的细胞分布。从即刻尸检或手术后获取年龄范围从青春期前女婴到绝经后成年女性的卵巢。结果揭示了芳香化酶在不同发育阶段表达的时间和空间变化。在2.5个月大的婴儿卵巢中未检测到免疫反应性芳香化酶。在绝经前卵巢中，基质区不存在芳香化酶，但在卵泡中，观察到芳香化酶表达的一致模式，这与卵泡大小和发育阶段有关。直径小于250微米的原始卵泡、初级卵泡或小次级卵泡中不表达芳香化酶。在稍大的卵泡（直径250 - 700微米）中，首先在少数卵泡膜细胞（TC）中检测到芳香化酶。在更成熟的次级卵泡直至大的排卵前卵泡（直径大于1厘米）中，TC芳香化酶免疫染色的强度和阳性细胞数量增加，反应定位于卵泡内膜（TI）/卵泡外膜界面的一层卵泡内膜细胞。在颗粒细胞（GC）中，芳香化酶首先在卵泡腔形成初始阶段（直径大于700微米）的卵泡中检测到，并且随着卵泡直径和卵泡腔增大染色增强，在排卵前卵泡中达到最强。GC芳香化酶总是在TI免疫染色存在的情况下被发现。这两个细胞群体被一层未染色的TI细胞分隔开，使卵泡壁呈现带状外观。免疫染色在壁层GC中最强，在卵泡腔GC细胞中较弱，在卵丘GC中不存在。在功能性黄体（CL）中也检测到免疫反应性芳香化酶，但在退化的CL和白体中不存在。我们的发现表明，CL的免疫染色细胞由以前的GC以及可能的以前TI细胞亚群组成。在围绝经期卵巢中，没有任何卵泡或基质芳香化酶免疫染色的证据。在绝经后卵巢中未观察到卵泡，但在7个标本中的3个标本的基质区中发现单个细胞和细胞簇有芳香化酶免疫染色反应。在所有情况下，芳香化酶免疫染色反应均在细胞质中。这些结果首次直接证明了TC芳香化酶以及绝经后女性基质细胞芳香化酶的存在。
