Cytochrome P450 aromatase in the testis of immature and mature pigs.

Aromatization of androgens into estrogens is performed by a microsomal enzyme, the cytochrome P450 aromatase. A direct approach for identifying the cellular source of aromatase is the use of immunohistochemistry with a specific antibody that recognizes aromatase. The pig presents some unusual features with regard to the synthesis of testosterone and estrogens in the male gonads.

Effect of photoperiod on the distribution patterns of androgen receptors and steroid hormone concentrations in ovaries of bank voles.

Cellular distribution patterns of the androgen receptor in ovaries of female bank voles, born and reared in long (18:6; LD) or short (6:18; SD) photoperiods, have been studied to understand effects of androgens in female gonads. The photoperiod is one of the most important factors in bank voles, which are seasonal breeders, that regulates both morphology and hormonal function of the ovary. Androgen receptors were visualized immunocytochemically, using a specific monoclonal antibody against androgen receptor protein.

Correlation between NADPH-diaphorase and iNOS in bank vole Leydig cells in vitro and in testicular sections with the use of histochemistry and immunocytochemistry.

Histochemistry for NADPH-diaphorase detects an enzymatic activity associated with nitric oxide synthase while immunohistochemistry detects the nitric oxide synthase molecule. NADPH-diaphorase and inducible isoform of nitric oxide synthase in Leydig cells in vitro and in testis sections of the bank vole were demonstrated histochemically and immunocytochemically. Histochemical studies revealed localization of NADPH-diaphorase reaction product in the cytoplasm of cultured Leydig cells as well as in the interstitial area, mainly in Leydig cells and in vascular endothelium.

Localization of the progesterone receptor in the porcine ovary.

Regulation of progesterone receptor (PR) expression has been studied in many species. However, precise studies have not yet been performed in the porcine ovary. We have examined the localization of PR in follicles and corpora lutea of the porcine ovary at different stages of their development.

The effect of testicular macrophages, macrophage-conditioned medium and interleukin-1alpha on the cytoskeleton of bank vole Leydig cells.

Recently, morphological and functional interactions between cytoskeletal elements and their involvement in cell movements, shape changes and/or translocation of organelles have been intensively studied. Thus, the aim of our work was to determine whether testicular macrophages and/or their products have an influence on Leydig cell cytoskeleton. The source of Leydig cells and macrophages were male bank voles from spring and autumn generations, reared in different regime of light for 7-8 weeks.