[Measurement of methionine-enkephalin-like substance in CSF from normal subjects and patients with pituitary adenoma (author's transl)].

Methionine-enkephalin-like substance was measured in CSF by the radioreceptor-assay established by Furui et al. Samples were obtained from preoperative 20 cases, in which were included 11 cases of pituitary adenoma, 3 cases of craniopharyngioma, 2 cases of pseudtumor cerebri and 4 normal cases, by lumbar puncture. Also postoperative measurement of this substance and pre- and postoperative measurement of ACTH in plasma were performed in 5 cases of Cushing's disease. Five ml of CSF was chromatograpied on two successive columns, lyophilized and assayed for opiate receptor affinity against 3H-dihydromorphine. Measured values were expressed as methionine-enkaphalin equivalents using the displacement curve run in parellel. Methionine-enkephalin-like substance level ranged from less than 0.5 to 20.0 pmoles/ml in all cases and mean value was 2.6 pmoles/ml (+/- 1.0 S.E.) in normal subjects. In Cushing's disease the level was not elevated preoperatively (2.1 +/- 0.3) and did not significantly decrease postoperatively (1.6 +/- 0.4 pmoles/ml) in contrast to the decrease of ACTH in plasma. It is suggested that methionine-enkephalin-like substance in CSF is not derived from ACTH producing cells of pituitary gland. One case of craniopharyngioma showed very high value. This case revealed diabetes insipidus at sampling. The possibility of participation of methionine-enkephalin in secretion of antidiuretic hormone was discussed.