نتایج جستجو برای: ovarian steroid production
تعداد نتایج: 723700 فیلتر نتایج به سال:
Organogenesis of the ovary is a highly orchestrated process involving multiple lineage determination of ovarian surface epithelium, granulosa cells and theca cells. Although the sources of ovarian surface epithelium and granulosa cells are known, the origin(s) of theca progenitor cells have not been definitively identified. Here we show that theca cells derive from two sources: Wt1(+) cells ind...
OBJECTIVE The luteal phase after ovarian hyperstimulation for in vitro fertilization (IVF) is insufficient. Therefore, luteal phase supplementation is routinely applied in IVF. It may be postulated that premature luteolysis after ovarian hyperstimulation is due to supraphysiological steroid levels in the early luteal phase. In the present study, high doses of steroids are administered after the...
BACKGROUND Ovarian tissue cryopreservation is the only option for preserving fertility in prepubertal girls and cancer patients requiring immediate treatment. Following ovarian tissue cryopreservation, fertility can be restored after tissue transplant or in vitro follicle maturation. METHODS Macaque (n= 4) ovarian cortex was cryopreserved using slow-rate freezing (slow freezing) or vitrificat...
To determine whether prolactin affects both luteal and follicular production of testosterone and oestradiol, pseudopregnant rats, either intact or hypophysectomized on day 8, were injected daily between days 8 and 9 with 1.5 i.u. human chorionic gonadotrophin (hCG), 250 micrograms prolactin or a combination of both. Control rats were given vehicle. On day 9, blood was obtained from the ovarian ...
The granulosa follicle cell of the Graafian follicle of the rabbit ovary differentiates into a lutein cell involved in steroid synthesis. Cytological events which occur within the granulosa cell of the normally stimulated follicle prior to ovulation have been duplicated by the intrafollicular injection of exogenous gonadotrophin. The luteinization of the granulosa cells involves the accumulatio...
The purpose of this chapter is to review the tissue-specific role of estrogen (E2) and progesterone (P4) in human endometrium and mammary gland. It is well known that both E2 and P4 are essential for the development and differentiation of human endometrium and mammary gland, but the exact basis for differential tissue-specific signalling of E2 and P4 are still not fully understood. This chapter...
A girl with steroid cell ovarian tumor misdiagnosed as non-classical congenital adrenal hyperplasia.
Ovarian steroid cell tumors are rarely encountered in prepubertal girls. The majority of these tumors produce hormones, testosterone being the leading one. These tumors may either coexist with or imitate congenital adrenal hyperplasia (CAH). We present a 13-year-old female patient who was diagnosed with non-classical CAH at six years of age while being investigated for premature pubarche. She w...
To understand the mechanism of sex differentiation in the protogynous Malabar grouper Epinephelus malabaricus, we performed an immunohistochemical investigation of the expression of three steroidogenic enzymes, cholesterol-side-chain-cleavage enzyme (CYP11a), aromatase (CYP19a1a), and cytochrome P45011beta-hydroxylase (CYP11b), in the gonads during ovarian differentiation. Strong positive immun...
Ovarian steroid metabolism was investigated (i) during development in a normal inbred strain in which post-natal follicle growth has been described and (ii) in adult hypogonadal (hpg) mice which lack GnRH and have very low serum concentrations of gonadotrophins. Tissue was incubated with [3H]pregnenolone or [3H]androstenedione and metabolites separated by t.l.c. or h.p.l.c. Progesterone was the...
BACKGROUND Steroid cell tumors of ovary account for less than 0.1% of all ovarian tumors and these tumours may present at any age in association with interesting presentations related to hormonal activities. The subtype, not otherwise specified (NOS), is associated with androgenic changes in 56-77% and Cushing syndrome in 6-10%. Due to the rarity of available data regarding these tumors, little...
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