1,721,050 research outputs found
Cobalt chloride, a hypoxia-mimicking agent, modulates redox status and functional parameters of cultured swine granulosa cells
No full textHypoxia occurs physiologically during ovarian follicle growth; this deprivation represents a
triggering stimulus for the production of vascular endothelial growth factor (VEGF) by proliferating
granulosa cells, which are mostly responsible for the growth of the follicle. Moreover, the
steroidogenic activity of these cells ensures a receptive environment for the implantation and
development of the early embryo. The present paper reports the adaptive response of swine
granulosa cells to cobalt chloride (CoCl(2), a chemical hypoxia-mimicking agent. The effects of the
treatment were evaluated on cell proliferation, steroidogenesis and VEGF production. In addition,
because mithocondrial reactive oxygen species (ROS) are possibly involved in O(2) sensing, ROS
levels and scavenging enzyme activity were investigated. In the present study, CoCl 2 had no effect
on progesterone production, although it significantly reduced oestradiol synthesis. The addition of
CoCl(2) to granulosa cell culture stimulated VEGF production and the generation of hydrogen
peroxide. Chemical hypoxia had different effects on scavenger enzyme activities: the activity of
superoxide dismutase was enhanced, that of peroxidase reduced and catalase activity was
unaffected. The net result is a 'pro-oxidant' state, which appears to be possibly involved in the
stimulation of VEGF production, thus inducing follicular angiogenesis
La stanniocalcina 1 è un potenziale regolatore fisiologico della steroidogenesi nel follicolo ovarico suino.
No full textThe phytoestrogen quesrcetin impairs steroidogenesis and angiogenesis in swine granulosa cells in vitro.
Full text linkExperimental evidence document that nutritional phytoestrogens may interact with reproductive functions but the exact mechanism of action is still controversial. Since quercetin is one of the main flavonoids in livestock nutrition, we evaluated its possible effects on cultured swine granulosa cell proliferation, steroidogenesis and redox status. Moreover, since angiogenesis is essential for follicle development, the effect of the flavonoid on Vascular Endothelial Growth Factor output by granulosa cells was also taken into account. Our data evidence that quercetin does not affect granulosa cell growth while it inhibits progesterone production and modifies estradiol 17 production in a dose-related manner. Additionally, the flavonoid interferes with the angiogenic process by inhibiting VEGF production as well as by altering redox status. Since steroidogenesis and angiogenesis are strictly involved in follicular development, these findings appear particularly relevant, pointing out a possible negative influence of quercetin on ovarian physiology. Therefore, the possible reproductive impact of the flavonoid should be carefully considered in animal nutrition
Bisphenol A interferes with swine vascular endothelial cell functions
No full textSeveral studies have demonstrated that the endocrine disruptor bisphenol A (BPA) negatively affects animal and human health. An angiogenic process has been suggested among the events disrupted by this molecule, but the underlying mechanisms have not yet been clarified. The effect of BPA on angiogenesis was investigated by means of a bioassay previously validated in our laboratory. Using immortalized swine aortic endothelial cell line (AOC), the development of new blood vessels through a three-dimensional in vitro angiogenesis assay was evaluated. Subsequently, since vascular endothelial growth factor (VEGF) and nitric oxide (NO) are key players in the regulation of the angiogenic process, the effect of BPA on the production of these molecules by AOC was examined. BPA (10 μmol/L) stimulated AOC growth (p < 0.05) and VEGF production (p < 0.05), but did not modify NO levels. Our data suggest that the endocrine-disrupting effects of BPA could also be associated with the promotion of vascular growth, thus interfering with a physiologically finely tuned process resulting from a delicate balance of numerous molecular processes. The stimulatory effects of BPA on VEGF production may have negative implications, potentially switching the balance toward uncontrolled neovascularization. Moreover, since angiogenesis is involved in several pathologies, including cancer growth and progression, potential health risks of BPA exposure should be carefully monitored
Ossido nitrico , steroidogenesi ed insorgenza di apoptosi della granulosa: studio comparativo nella specie bovina e suina
No full textIs nitric oxide an autocrine modulator of bovine granulosa cell function?
No full textNitric oxide (NO) is an important intra- and intercellular messenger controlling many biological processes. It is synthesized by NO synthases, which have been found also in granulosa cells. The present study examined whether NO is present in bovine follicular fluid and is produced by granulosa cells in culture. Secondly, it aimed to determine if NO affects the main parameters of granulosa cell function. The NO donor S-nitroso-L-acetyl-penicillamine (10(-3), 10(-4), 10(-5) M) was used to evaluate whether NO might influence steroidogenesis, proliferation and apoptosis in bovine granulosa cells collected from follicles divided according to their size in small (8 mm). The data demonstrate the presence of NO in follicular fluid and its production by granulosa cells in culture: the most active cells in producing NO are those from the small follicles, as confirmed by the NO levels in follicular fluid. This study also shows that NO donor significantly (P<0.001) inhibits progesterone (P4) and oestradiol 17 beta (E2) production by the granulosa cells from both kinds of follicle; moreover, the highest concentration of NO donor significantly (P<0.001) inhibits DNA fragmentation in all the cells whereas the lowest concentration stimulates (P<0.001) cellular apoptosis only in granulosa cells from large follicles. NO donor does not seem to modify cell proliferation. Taken together these data lead point to NO as a local modulator of granulosa cell function
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