Comparison of transforming growth factor β1 concentrations in the ovaries of rats stimulated by human menopausal gonadotropin or recombinant follicle-stimulating hormone

Objective: To compare the effects of human menopausal gonadotropins (hMG) and recombinant follicle stimulating hormone (rFSH) on transforming growth factor (TGF) β1 concentration in the rat ovary.

Study design: Twenty-one fertile Wistar-Albino rats were divided into 3 groups of 7. Groups 1, 2 and 3 were injected with saline, hMG or rFSH, respectively, over 5 days, after which they underwent ovariectomy. Hematoxylin and eosin (H&E) staining was used for histological examination. TGF β1 staining levels in ovarian stroma, vessel walls, granulosa cells of Graafian follicles and corpus luteum cells were investigated immunohistochemically.

Results: On histological examination, the number of smaller antral follicles was higher in the control group, while there were more and larger antral follicles in the hyperstimulated groups. There were statistically significant differences in staining in vessel walls and granulosa cells between the control and stimulated groups. Both stimulation protocols caused an increased TGF β1 concentration in vessel walls, while there was weak staining in granulosa cells in the treatment groups compared to the control group (p<0.05). There were no significant differences in staining scores between the two treatment groups (p>0.05).

Conclusions: The effects of two different gonadotropin preparations on TGF β1 concentrations in different localizations in the rat ovaries are comparable. It may be postulated that the luteinizing hormone (LH) content of hMG contributes little or nothing to the TGF β1 mediated angiogenesis.