Structural relationships between the chick oviduct progesterone receptor A and B proteins

Histomorphometric and progesterone receptor immunohistochemical analysis in the oviduct of newly hatched chicks treated with follicle-stimulating hormone during embryonic development

In this study we evaluated the histomorphology and ultrastructure of the oviduct of newly hatched chicks, as well as the immunohistochemical expression of progesterone receptor (PR) in this tissue after follicle-stimulating hormone (FSH) treatment on days 13, 15 and 17 of embryonic development. Results indicated a marked difference in the histology of the oviduct of newly hatched chicks treated with FSH. Magnum mucosa from these animals presented a pseudostratified epithelium with evaginations from the lumen into the epithelium and from the latter into the stroma beneath where tubular glands are formed. In contrast magnum mucosa from control animals presented columnar epithelium with no evaginations. In magnum epithelium FSH also induced the formation of cilia and microvilli projections into the lumen as well as an increase in the wall and lumen areas and in the density of nuclei per unitarea. PR immunoreactivity was only observed in the oviduct of FSH treated animals. PR was located in the nucleus of epithelial luminal cells, mucosal stromal cells and smooth muscle cells. These findings suggest that FSH induces an adequate hormonal milieu for the cytodifferentiation and PR gene expression in the chick oviduct.

Correlation between tyrosine hydroxylase activity, melanogenesis, and estradiol binding in human melanoma cells

Cytosols fractions from human mammary carcinoma, or malignant melanoma cells, and tyrosine hydroxylase (TH) bind 3H-estradiol (3H.E) with strong affinity. Monoclonal antibodies secreted by cloned cell hybrids which were formed by the fusion of murine myeloma cells with spleen cells from BALB/c mice pre-immunized with purified TH were used to differentiate between 3H.E-binding protein in the cytosols of various neoplastic cells. These monoclonal TH-antibodies inhibited the enzymic activity and the binding of 3H.e to TH or to cytosol fractions of melanotic melanoma cells, but had no effect on 3H.E binding to cytosol fractions from various mammary epithelial or carcinoma cell lines. Cultivation of estradiol-responsive melanotic melanoma cells in media supplemented with the TH-antibodies, caused loss of pigmentation, the cells became amelanotic and non-responsive to 17 beta-estradiol. The results indicate that the estrogen does not bind to melanoma cells via a receptor as for mammary carcinoma cells but to tyrosine hydroxylase.

The binding of [3H]oestradiol-receptor complexes to calf uterine chromatin

Various aspects of the interaction of oestrogen-receptor complexes with calf uterine chromatin covalently coupled to cellulose were analysed. Partially purified [3H]oestradiol-receptor complexes were bound to intact, or partially deproteinized, chromatin resins. Proteins were removed from the chromatin-cellulose resins by extraction with high molarities of salt, including NaCl/urea, guanidine hydrochloride and guanidine thiocyanate. After extensive washing to remove the salt, [3H]oestradiol-receptor-complex solutions were added to the resins and the degree of binding was determined. The extent of [3H]oestradiol-receptor-complex binding to chromatin was enhanced by extraction of chromosomal proteins. By varying the molarity of the salt, and consequently the extent of protein removal, it was possible to resolve [3H]oestradiol-receptor-complex binding to guanidine thiocyanate-extracted chromatin into two components. Similarly, [3H]oestradiol-receptor-complex binding to guanidine hydrochloride-treated chromatin included three regions of enhanced binding capacity. The [3H]oestradiol-receptor-chromatin interaction was saturable with respect to both intact and salt-extracted resins. Thus uterine chromatin may contain three or more specific classes of acceptors for the oestrogen-receptor complex.