Immunohistochemical Localization of Basic Fibroblast Growth Factor (bFGF) within Growing and Atretic Mouse Ovarian Follicles

Abstract

Basic fibroblast growth factor is a biologically active peptide with a strong affinity for heparin. This growth factor has been previously shown to be mitogenic for a variety of mesoderm and neuroectoderm-derived cells. The immunohistochemical localization of basic FGF within mouse growing and atretic ovarian follicles is presented in the study. Ovarian tissue samples were obtained either (a) randomly from mice housed in a controlled light environment or (b) following the administration of exogenous gonadotropins to stimulate follicle development. Ovarian samples were fixed in Bouin's fluid for no longer than 18 h. Following fixation and paraffin embedding, sections were exposed to a primary antibody made in rabbits against either (a) human recombinant basic FGF or (b) the 1-24 synthetic fragment of bovine basic FGF. The primary antibody was followed by biotinylated goat anti-rabbit IgG and a biotin-avidin-peroxidase complex. There were no differences in the immunolocalization of basic FGF using either source of primary antibody or between randomly obtained ovarian samples and those obtained from mice given exogenous gonadotropins. Basic FGF was immunolocalized in follicle basal laminae and was also closely associated with individual follicle cells during all stages of ovarian follicle development. Basic FGF was absent in the theca interna, oocyte cytoplasm, zona pellucida and follicle fluid of normal growing follicles. Individual corpora luteal cells were surrounded by basic FGF but lacked cytoplasmic staining. Atretic follicles exhibited staining patterns similar to their respective stage of follicle development. However, when present, follicle fluid within atretic follicles was strongly positive for basic FGF. These results indicate that basic FGF may be an important factor involved in intraovarian control mechanisms.

The in vivo effects of fibroblast growth factor and epidermal growth factor on the secretion of oestradiol, androstenedione and progesterone by the autotransplanted ovary in the ewe

“…There was also no observable effect of FGF on progesterone secretion even though FGF expression has been detected in bovine luteal cells (Stirling et al 1990(Stirling et al , 1991. Others have detected, by immunocytochemistry, FGF in bovine large luteal cells (Schams et al 1993) while in another study, FGF was immuno-localised around luteal cells but lacked any cytoplasmic staining (Wordinger et al 1993). Clearly more information is required to clarify the exact role of FGF in the large luteal cell.…”

“…Since heparin binds FGF (Yayon et al 1991, Mansukhani et al 1992) and enhances FGF binding to its receptor (Roghani et al 199A) it is likely that this had a stimulatory effect in this experiment and enhanced the action of FGF on steroidogenesis. FGF also binds to components of the basal lamina in the follicle (Wordinger et al 1993) and to components of the extracellular matrix (Gonzalez et al 1990, Carlone & Rider 1993. It has been suggested that this binding is an important regulatory mechanism of FGF's cellular actions (Logan & Hill 1992).…”

Role of Fibroblast Growth Factors and Their Receptors in Mouse Primordial Germ Cell Growth1

“…Mice lacking a functional FGFR-2 are not presently available. FGF may play important roles during gametogenesis, as bFGF has been detected both in murine ovarian follicles [39] and in rat spermatocytes [40]. Another member of this growth factor family, FGF-8, may also be present in prespermatogonia between 15 and 17 dpc [41].…”

Ultrastructure and morphometry of ovarian follicles in the armadillo Chaetophractus villosus (Mammalia, Dasypodidae)

“…Although this fact differentiates the armadillo's ovary from the mouse's one, in which this sort of primordial follicles are found exclusively in the prenatal stage (Wordinger et al, 1993), it resembles the ovary of other primitive mammals (Falconnier & Kress, 1992;Maitland & Ullmann, 1993).…”