Plasma pituitary hormones in patients with Parkinson's disease treated with bromocriptine.

Bromocriptine was used for Parkinson's disease in 15 patients for 20 weeks. Immunoreactive plasma lutrophin (LH), follitrophin (FSH), prolactin, and somatotrophin (GH, growth hormone) concentrations were analysed before and during the treatment. Plasma prolactin levels were very markedly reduced during treatment. Plasma lutrophin levels were increased significantly in female patients, but not in male patients. No changes were noticed in follitrophin levels, but plasma somatotrophin levels were reduced during treatment. No correlations were found between the degree of clinical response and changes in plasma gonadotrophin and somatotrophin. This suggests that the effects of bromocriptine on extrapyramidal and neuroendocrine dopaminergic neurones are unrelated. We suggest careful and frequent controls of neuroendocrine secretion patterns in patients with Parkinson's disease who are treated with high doses of dopamine receptor stimulators, since the response of some pituitary hormones to bromocriptine are very marked.