Dynamic evaluation of prolactin secretion in patients with oligospermia: effects of treatment with metergoline.

Serum prolactin levels were measured in 50 patients with oligospermia and in 20 control subjects under fasting conditions and following the administration of levodopa, pyridoxine, metoclopramide, and synthetic thyrotropin-releasing hormone. Four patients (8%) under fasting conditions had prolactin levels slightly above the normal range. However, no significant differences in prolactin behavior were detected between patients with hyperprolactinemia, patients with normal prolactin levels, and control subjects. The four patients with hyperprolactinemia were treated with metergoline, an ergoline derivative. Metergoline administration promptly reduced the prolactin levels. Spermatogenesis was restored in three patients after 4 to 5 months of treatment.