Specific prolactin release refractoriness to thyroid-stimulating hormone-releasing factor in an obese infertile man.

A specific PRL unresponsiveness to TSH-releasing factor was uncovered during the workup of an obese man with infertility due to oligozoospermia. Normal PRL responses were demonstrated in response to insulin-induced hypoglycemia, MTC, and sleep. Borderline-low circulating T without elevated baseline LH levels which rose in response to clomiphene citrate and normal LH and FSH responses were noted after LH-RH administration, indicating normal pituitary responsiveness, even though occurring in the presence of hypothalamic dysfunction, affecting pituitary gonadal relations, appears located in the pituitary and limited to a single stimulus: TSH-releasing factor.