Role of ghrelin in regulating rabbit ovarian function and the response to LH and IGF-I

Expression and localization of ghrelin and its receptor in ovarian follicles during different stages of development and the modulatory effect of ghrelin on granulosa cells function in buffalo

“…cation of ghrelin effects on the expression of selected markers of proliferation and apoptosis fully supported the data obtained previously on porcine ovarian GCs and whole follicles [Rak and Gregoraszczuk, 2008;Rak et al, 2009]. Similarly, in ghrelin treated GCs of rabbit ovary, cellular proliferation was promoted and apoptosis was inhibited (Sirotkin et al, 2009), however, ghrelin promoted both proliferation and apoptosis in chicken ovarian cells (Sirotkin et al, 2006). The possible mechanism of granulosa cell proliferation by ghrelin through activation of ERK1/2, PI-3 kinase pathway and accumulation of PCNA in cells.…”

“…In earlier study, we observed inhibitory effect of ghrelin in luteal cell culture in buffalo (Gupta et al, 2014). The present study is fully supported by earlier studies in which ghrelin suppressed E2 secretion from cultured granulosa cell in human (Viani et al, 2008), chicken (Sirotkin and Grossmann, 2008) and rabbit (Sirotkin et al, 2009). However, the present findings do not agree with observations of Rak and Gregoraszczuk (2008) in porcine species, in which ghrelin increased E2 secretion from cocultured granulosa and theca cells.…”

“…The possible mechanism of granulosa cell proliferation by ghrelin through activation of ERK1/2, PI-3 kinase pathway and accumulation of PCNA in cells. (Sirotkin et al, 2009;Rak-Mardyla and Gregoraszczuk, 2010). Estradiol also promote ovarian cell proliferation by directly increasing PCNA expression (Wang et al, 2008).…”

“…Then the cells were centrifuged, resuspended and plated out at 1.5 Â 10 5 viable cells per well in a 24-well plate (total volume: 1 ml containing 10% Fetal Bovine Serum (Sigma) and Antibiotic & Antimycotic solution (Penicillin-G 100U/ml, Streptomycin 100 lg/ml, Amphotericin 0.25 lg/ml (SV30079.01; Hyclone, Thermo Scientific) in a humidified CO2 (5%) incubator at 38.5°C. The cells were allowed to attach and grow (75-80% confluent) for 48 h and there after the media was replaced with fresh media containing different concentrations (1, 10, and 100 ng/ml) of ghrelin and were maintained for 48 h. The doses of the ghrelin were selected based on the earlier report (Sirotkin et al, 2009;Sirotkin and Meszarosova, 2010). Control cells were grown in media without ghrelin.…”

Ghrelin Negatively Affects the Function of Ovarian Follicles in Mature Pigs by Direct Action on Basal and Gonadotropin-Stimulated Steroidogenesis

“…Pretreatment of rabbits with ghrelin stimulated, suppressed, or even reversed subsequent LH and IGF-I effects on hormone secretion by cultured granulosa cells. 37 The present study indicated very clearly that ghrelin may be one of the hormones responsible for regulation of ovarian steroidogenesis in mature pig. Similar to other appetite hormones or adipokines, ghrelin has autocrine or paracrine effects on porcine ovarian steroid synthesis.…”