Expression of the neural cell adhesion NCAM in endocrine cells of the ovary

In the adult mammalian ovary morphogenesis and differentiation
processes are under hormonal control and, thus, occur in a highly
regulated way during the sexual cycle. Cell-cell interactions, such
as cell adhesion and cell separation, are crucial during these
events. Here we show that the ovarian endocrine cells, which are
prototypes of steroid-producing cells, express neural cell adhesion
molecules (NCAMs). The combined use of in situ hybridization
histochemistry, immunocytochemistry at the light and electron
microscope levels, S1 nuclease protection assays, and Western
blotting revealed that in the ovary of the adult rat during the
estrus cycle and pregnancy, NCAM mRNA and the 140-kDa isoform of
this protein are expressed mainly in granulosa cells of growing
preantral and antral follicles and in corpora lutea. Since the
granulosa cells lining the forming antrum and the antral fluid were
strongly immunoreactive, a role for NCAM in the formation of the
follicular antrum is proposed. The expression of NCAM was also
associated with luteal cells of the active corpus luteum,
indicating a role for NCAM in the morphogenesis of this endocrine
compartment. Moreover, thecal cells of large follicles and
hypertrophic thecal cells of atretic follicles expressed NCAM, as
did interstitial cells, which are derived from thecal cells of
atretic follicles. We propose that the adhesion molecule, NCAM, is
an important factor involved in the recognition and intercellular
interaction of ovarian endocrine cells and, thus, participates in
the regulation of the cyclic remodeling processes of the ovarian
endocrine compartments