Background: Germ cell development processes are influenced by soluble factors and intercellular signaling events between them and the neighboring somatic cells. More insight into the molecular biology of the germ cell development from embryonic stem (ES) cells and investigation of appropriate factors, specifically those targeting differentiation process, is of great importance. In this study, w...

Maintenance of pregnancy in the rat requires the corpus luteum. At a time when rat placental lactogens (rPLs) are required to support progesterone production by the corpus luteum and when relaxin expression is initiated, expression of a specific protein kinase C (PKC) isoform, PKC d, is dramatically increased. We therefore assessed whether prolactin (PRL) receptor activation promotes activation...

To investigate the early ovarian changes after cyclophosphamide treatment, immature rats primed for 48 h with pregnant mare serum gonadotropin were given injections i.p. of cyclophosphamide (100 mg/kg) at 1, 2, 4, 16, and 24 h before decapitation. Serum estradiol dropped significantly after 24 h of exposure to cyclophosphamide (P less than 0.001). Following 16 and 24 h of cyclophosphamide expos...

Expression of pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide with considerable homology to vasoactive intestinal peptide, has been shown to be stimulated by gonadotropins in the ovary. The present studies further evaluated the cell-type specific expression and gonadotropin regulation of PACAP type I receptor (PACAPR) messenger RNA in immature rat ovaries and in cultu...

The production of plasminogen activator by ovarian granulosa cells has been previously reported to be temporally correlated with ovulation in the rat and to be under hormonal control of gonadotropins. We have examined the type of plasminogen activator produced by granulosa cells and also investigated other ovarian cell types for synthesis of this enzyme. Using antibodies specific for tissue-typ...

Background: Involvement of Wnt proteins and one of its antagonist known as secreted Frizzled Related Protein type-4 (sFPRP-4) was reported in rodent ovarian follicular development. Other studies showed an ap- Abstracts of the 11th Royan International Congress on Reproductive Biomedicine 7 7 International Journal of Fertility & Sterility (IJFS), Vol 4, Suppl 1, Summer 2010 optotic-associated exp...

objective: the purpose of the present study was to verify the ultrastructural characteristics of cultured mouse preantral follicles from fresh and vitrified –warmed ovarian tissues. materials and methods: the ovaries of 14-day-old mice (n = 5) were vitrified using a mixture of ethylene glycol, ficoll 70 and sucrose. the preantral follicles were isolated and cultured in α-minimum essential mediu...

background and objective: histopathological evaluation of granulosa cell tumors (gct) of the ovary may be confused morphologically with a wide variety of the tumors. immunohistochemical staining for inhibin and calretinin can be used for better diagnosis. although it has been suggested that inhibin can be a sensitive marker for gct, it maybe had negative results in some cases.  in addition, cal...

Atresia, a degenerative process through which many follicles are removed from the growing pool, involves apoptotic changes in the follicular granulosa cells. To identify histochemical markers of early stages of atresia, an in-vivo rat model was used which allowed the study of atresia of pre-ovulatory follicles in a synchronized and chronological order. By blocking the pre-ovulatory luteinizing ...

Rat ovarian granulosa rely heavily on lipoprotein-derived cholesterol for steroidogenesis, which is principally supplied by the LDL receptor- and scavenger receptor class B type I (SR-BI)-mediated pathways. In this study, we characterized the hormonal and cholesterol regulation of another member of the LDL receptor superfamily, low density lipoprotein receptor-related protein (LRP), and its rol...