Intercellular communication within the rat anterior pituitary gland: VI. Development of gap junctions between folliculo-stellate cells under the influence of ovariectomy and sex steroids in the female rat.
BACKGROUND
Farquhar (1957) initially described the folliculo-stellate cells in the rat anterior pituitary gland and found them to be located in groups around follicles throughout the anterior lobe. Soji and his co-workers have published a series of reports concerning cell-to-cell communication in the male rat hypophysis involving folliculo-stellate cells as mediated through a gap junctional network and recorded a reduction in junctional number following castration that was reversed by the administration of testosterone (Soji and Herbert, 1990, Anat. Rec., 226:342-346; Soji et al., 1990, Anat. Rec., 226:337-341).


METHODS
Animals were ovariectomized at 10 days of age and separated into three groups: (1) intact control, (2) ovariectomized controls, (3) ovariectomized and given either estradiol, testosterone, or progesterone. On days 10, 20, 30, 40, and 45, the pituitary gland from animals in each group was removed and processed for ultrastructural examination.


RESULTS
Gap junctions in the intact control female rats initially appeared between adjacent folliculo-stellate cells on day 20. Their numbers linearly increased until the animals reached the age of 45 days. In contrast, there was a suppression in the number of gap junctions present in the ovariectomized groups and a marked enhancement of the junctions in each of the three steroid-treated groups.


CONCLUSIONS
These findings support the observations made in the male rat in which it was found that the development of gap junctions in the anterior pituitary gland of the rat is dependent in part on the presence of sex steroid hormones.
Kurono
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Department of Anatomy, Nagoya City University Medical School, Aichi, Japan.
D000818:Animals; D002450:Cell Communication / Q000187:drug effects; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D007365:Intercellular Junctions / Q000187:drug effects; D008854:Microscopy, Electron; D010052:Ovariectomy; D010903:Pituitary Gland, Anterior / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D012739:Gonadal Steroid Hormones