Hormonal Stimulation in a Gonadal Dysgenesis Mare.

This research article examines the hormonal responsiveness of an X0 mare, more specifically its uterus and ovaries, after treatment with hormones as the mare was displaying signs of gonadal dysgenesis.

Introduction and Background

• The main goal of the report was to determine the efficacy of hormonal treatment on a mare showing signs of gonadal dysgenesis, a genetic disorder identified by underdeveloped or malformed gonads (ovaries).
• The mare had some anomalies in its reproductive organs, including a flaccid and smaller than normal uterus, and small, smooth ovaries; indicative of the abnormality. Further anatomical analysis also revealed that the endometrium (inner lining of the uterus) had normal architecture, but an atrophic glandular epithelium.
• The horse was karyotyped, a method used to identify the number of chromosomes an organism has, which showed that 70 cells contained only 63 chromosomes, one less than normal for horses, implying missed sex chromosome.

Methods

• Testing for the hormone levels in the mare’s bloodstream was carried out. This included testing the levels of estrogens, progesterone, testosterone, FSH (Follicle Stimulating Hormone), and LH (Luteinizing Hormone) in the horse’s body.
• In addition, immunohistochemistry tests were administered to determine the presence of both estrogen and progesterone receptors in the endometrial samples.
• A hormone administration regimen was initiated which included the introduction of 17β estradiol on three consecutive days followed by a long-action progesterone intake on the fourth day.

Observations and Findings

• The response to hormonal stimulation in the mare led to significant changes in endometrial ultrasonography and histology.
• Production of estradiol caused uterine edema (swelling), while progesterone reduced this edema.
• Unfortunately, the mare was not followed up with further treatment or monitoring at the behest of the owner, thus limiting the understanding of long-term effects of the hormonal therapy.
• Overall the findings indicated that while the endometrium seemed to be functional and responsive to hormone treatment, no significant changes in the ovaries were noticed. This suggests that the ovarian abnormalities present in the mare were not rectified by the treatment.