Effects of Steroid Hormone in Avian Follicles

Abstract

The aim of the present study was to examine the effects of testosterone (T) and estradiol-17β (E2) on the production of progesterone (P4) by granulosa cells, and of the E2 on the production of P4 and T by theca internal cells. In the first experiment, granulosa cells isolated from the largest (F1) and third largest (F3) preovulatory follicle were incubated for 4 h in short-term culture system, P4 production by granulosa cells of both F1 and F3 was increased in a dose-dependent manner by ovine luteinizing hormone (oLH), but not T or E2. In the second experiment, F1 and F3 granulosa cells cultured for 48 h in the developed monolayer culture system were recultured for an additional 48 h with increasing doses of various physiological active substances existing in the ovary, including T and E2. Basal P4 production for 48 h during 48 to 96 h of the cultured was about nine fold greater by F1 granulosa cells than by F3 granulosa cells. In substances examined oLH, chicken vasoactive intestinal polypeptide (cVIP) and T, but not E2, stimulated in a dose-dependent manner P4 production in both F1 and F3 granulosa cells. In addition, when the time course of P4 production by F1 granulosa cells in response to oLH, cVIP, T and E2 was examined for 48 h during 48 to 96 h of culture, although E2 had no effect on P4 production by granulosa cells of F1 during the period from 48 to 96 h of culture, P4 production with oLH was found to be increased at 4 h of the culture, with a maximal 9.14 fold level at 6 h. By contrast, P4 production with cVIP and T increased significantly (p<0.05) from 8 and 12 h of the culture, respectively, with maximal 6.50 fold response at 12 h and 6, 48 fold responses at 36 h. Furthermore, when F1 granulosa cells were precultured with E2 for various times before 4 h culture with oLH at 96 h of culture, the increase in P4 production in response to oLH with a dose-related manner was only found at a pretreatment time of more than 12 h. In the third experiment, theca internal cells of F1, F2 and the largest third to fifth preovulatory follicles (F3-5) were incubated for 4 h in short-term culture system with increasing doses of E2. The production of P4 and T by theca internal cells were increased with the addition of E2 of 10−6 M. These increases were greater in smaller follicles. These results indicate that, in granulosa cells of the hen, T may have a direct stimulatory action in the long term on P4 production, and on E2 in long-term action which may enhance the sensitivity to LH for P4 production, and thus, in theca internal cells, E2 in short term action may stimulate the production of P4 and T.

FASN-Mediated Lipid Metabolism Regulates Goose Granulosa Cells Apoptosis and Steroidogenesis

“…Despite that the responses of the steroidogenesis-related gene expression levels in phGCs were not that consistent with those in hGCs for the stimulation of FASN overexpression, the result was no effect on P 4 production in the two categorized GCs. Besides the stimulation of gonadotropins (Rivas et al, 2015), steroidogenesis is also stimulated by other physiological active substances existing in the follicles (Groothuis et al, 2005). According to our results, the increasing fatty acids induced by overexpression of FASN were not such substances that could effectively stimulate the steroidogenesis in goose GCs from the follicles at different stages of development.…”

Characterization of the hypothalamo–pituitary–gonadal axis in low and high egg producing turkey hens

“…Within the hypothalamus, gonadotropin releasing hormone ( GNRH ) and gonadotropin inhibitory hormone ( GNIH ), both acting through their respective G-protein coupled receptors on pituitary gonadotroph cells, regulate gonadotropin production (Bédécarrats et al, 2009 ). Within the ovary, steroid hormone feedback loops regulate gene expression locally as well as in the hypothalamus and pituitary (Ottinger and Bakst, 1995 ; Caicedo Rivas et al, 2016 ). The largest preovulatory follicle ( F1 ) is responsible for the majority of progesterone production, the fifth largest preovulatory follicle ( F5 ) is responsible for the majority of androgen production, and the small white follicles ( SWF ) are responsible for the majority of estradiol production (Lee and Bahr, 1994 ).…”

Functional Morphology of Thecal Glands in the Ovary of Japanese Quails (<b><i>Coturnix japonica</i></b>)

“…Several authors [Dahl 1970[Dahl , 1971[Dahl , 1972Caicedo Rivas et al, 2016] studied the thecal glands in the hen (G. domesticus) in detail and the influence of steroids [Dahl, 1971;Caicedo Rivas et al, 2016], tamoxifen, and clomiphene on their ultrastructure. Therefore, the quail is only the second avian species where the thecal glands have been analysed on an ultrastructural level and the 2 cell types, SPCs and the ENCs, which contribute to thecal glands, have been characterised more closely using electron microscopy and immunohistochemical techniques in the present paper.…”