Die differenzierte Struktur und Funktion der Granulosa und Theka in verschiedenen Follikelstadien menschlicher Ovarien

Abstract

In a first paper, the structural and functional relationship of granulosa and theca of follicles during early development stages was reported. On the special question of whether and from which moment these two tissue formations are involved in the steroidbiosynthesis, our electronmicroscopic examinations have given a further insight to this. Neither the granulosa nor the theca folliculi of primordial, primary and secondary follicles show definite morphologic submicroscopic criteria of the steriodbiosynthesis. In the resting tertiary follicle, the electronmicroscopy defines the theca cells as steroidbiosynthetic active cells, whereas the granulosa cells of this stages of follicle demonstrate the morphologic characteristics of protein-synthetic active cells. Our, under physiological conditions, systematically conducted light and electronmicroscopic studies of preovulatory and freshly ruptured follicles showed remarkable structural changes in the granulosa, as well as in the theca folliculi. For the follicle granulosa cells of the preovulatory follicle, the studies could demonstrate a structural transformation process of proteinsynthetic active to steroidbiosynthetic active cells. This transformation process can be seen in the nucleus. Especially recognizable is the continuous change from rough to smooth endoplasmatic reticulum in the cytoplasm of most of the follicle granulosa cells, which apart from that, often displayed whorle-like formations. Furthermore, we noticed striking changes of the paraplasmatic structures, especially of the fat, present in various stages in the cytoplasm of the follicle granulosa cells. We also noticed large mitochondria, which showed a lot of vesicular cristae. Numerous existing Golgi-fields contained many little homogenous fat-like droplets, which were surrounded by a thin osmiophilic membrane. This recognizable transformation process of the proteinsynthetic active granulosa cells to the steroid cells is quite completed in freshly ruptured follicles, according to our examinations. Although the theca cells have already been defined submicroscopically in the resting tertiary follicle as steroidbiosynthetic active cells, we see in this cellgroup in the preovulatory, as well as in the freshly ruptured follicle a remarkable conspicuous size-increase of the mitochondria. Apart from that, there are wide areas which are solely occupied by smooth endoplasmatic reticulum, whereas other structures, for example fat, are scarely seen. As our examinations have shown, there is a close relationship between the transformation process in the granulosa and the theca of preovulatory follicles and the theca of preovulatory follicles that, the increasing concentration of progesteron in serum, which begins prior to the ovulation can be regarded as a product of the follicle granulosa cells being transformed to steroid cells.

Ovarian Production of Estrogens in Postmenopausal Women

“…At present, however, it is known that the adrenal gland produces a nonandrogenic compound-androstenedione, which is then converted in peripheral tissues into estrone (28). In the present study, we found an H S D enzyme and organelles in the cells of some postmenopausal ovaries, which indicates the possibility of steroidogenesis of the cell as shown by Grisp et al (8), Bara and Andersson (2) and Mestwerdt et al (20). Thus, since we also found higher levels of estrone and estradiol in the effluent blood of the ovary than in the cubital venous blood, we suggest that the postmenopausal ovary is also able to produce estrogens, either directly or by conversion of androgens.…”

Immunocytochemical localization of aromatase in ovaries of some rodents, cow and human.

“…The theca interna cells, interstitial gland cells and corpus luteum cells show these structures in their cytoplasm (5,12,14,25), and it is reasonable to consider in morphological aspects that these cells have an activity to produce estrogens.…”

Structure-Function Relationships in the Wall of the Ovarian Follicle

“…Details of the ultrastructure of the theca interna, and its changes during the later stages of follicular growth, have now been reported in the rat (Belt 1962), cow (Priedkalns et al 1968), horse , mouse (Hiura and Fujita 1977), pig (Krzysztofowicz and Stoklosowa 1977), man (Mestwerdt et al 1977) and sheep (O'Shea et al 1978a). A reasonably consistent picture emerges.…”

“…The major ultrastructural features of follicular epithelial cells at various stages of follicular growth have now been documented in several species including the rat (Bjorkman 1962), cow (Priedkalns and Weber 1968), sheep (Hay and Moor 1975a;Cran et al 1979), Rhesus monkey (Amin et al 1976) and man (Mestwerdt et al 1977). In preantral and antral follicles these cells have a relatively high nuclear: cytoplasmic ratio, and contain a wide range of cytoplasmic organelles.…”

“…Lysosomes (Krzysztofowicz andStoklosowa 1977), coated vesicles (O'Shea et al 1978a), microtubules and microfilaments (Mestwerdt et al 1977) have also been observed in theca interna cells, and comments on these structures in relation to the follicular epithelium are generally applicable to the theca.…”