The role of prostaglandins in the anti-apoptotic action of transforming growth factor alpha in hen granulosa cells.
|Title:||The role of prostaglandins in the anti-apoptotic action of transforming growth factor alpha in hen granulosa cells.|
|Abstract:||Most ($>$99%) ovarian follicles will succumb to atresia via a process known to involve apoptosis of granulosa cells. TGF$\alpha$ is mitogenic in hen granulosa cells and prostaglandins have been shown to mediate the actions of this growth factor in several cell types. The role of non-gonadotropin survival factors (e.g. TGF$\alpha)$ may be crucial in determining the eventual fate of prehierarchal follicles (atresia vs. ovulation). Hematoxylin and eosin stained histological sections of healthy prehierarchal follicles (2-6 mm) appeared to be morphologically unspoiled, round, with intact layers of granulosa cells. In contrast, same size atretic follicles appeared to be morphologically spoiled, with a diminished yolk space containing detached granulosa cells. In situ 3$\sp\prime$-end labelling of DNA in healthy follicles failed to display fragmented DNA in the granulosa or theca layers. However, granulosa cells of atretic follicles stained intensely for fragmented DNA, whereas theca layers showed little or no DNA fragmentation, consistent with the notion that ovarian follicular atresia is linked to apoptosis of granulosa, but not theca cells in vivo. An in vitro cell culture system was used to investigate if TGF$\alpha$ suppresses granulosa cell apoptosis and whether prostaglandins (PGs) mediate the anti-apoptotic action of TGF$\alpha.$ (Abstract shortened by UMI.)|
|Collection||Thèses, 1910 - 2010 // Theses, 1910 - 2010|