Effect of chronic treatment with [D-Ala6, des-Gly-NH210]LHRH ethylamide on ovarian histology in the rat.

The effect of chronic treatment with the LHRH agonist [D-Ala6, des-Gly-NH210]LHRH ethylamide (LHRH-A) on ovarian histology was studied in adult female rats injected with 5 micrograms of the peptide, once every second day, for 0, 2, 4 or 8 weeks. Using light microscopy, we examined the number of small medium, large and atretic follicles, as well as the number of normal and regressing corpora lutea. Using the point-counting method, we measured the relative surface occupied by luteal cells. It was found that treatment with LHRH-A for up to 8 weeks led to no significant change in any of the parameters studied. Moreover, resumed meiotic maturation of an abnormally high number of atypical fragmentations of the ova could not be observed. At least at the dose used, the LHRH agonist does not appear to induce any histological alteration in ovarian morphology and supports the potential clinical use of LHRH agonists as a new approach in female contraception and for the treatment of estrogen-dependent pathologies.