抄録
In order to study the effect of bromocriptine on prolactinoma, the gel filtration chromatographic behavior of prolactin was measured in both serum and cerebrospinal fluid (CSF) of six cases of prolactinoma which showed high concentration of prolactin after surgery and administration of bromocriptine. Prolactin levels of paired blood and CSF samples were measured by using a doubleantibody radioimmunoassay. Molecular weights of prolactin were estimated using an Ultrogel AcA 44® column with standard molecular markers. Although the postoperative prolactin level in serum decreased from 1, 657 ng/ml to 468 ng/ml on the average, the prolactin level in CSF showed an increase from 761 ng/ml to 1, 503 ng/ml on average. Long term administration of bromocriptine contributed to normalizing the prolactin level in serum. However, the level in the CSF could not be settled in the normal range. Gel filtration of serum and CSF gave three types of prolactin with different molecular weights: “little” “big” and “big-big”. In postoperative serum samples, the proportions of the three components were 71±4%, 19±2%, and 10±4%, respectively. In postoperative CSF samples, the proportions were 96±2%, 2 ±1%, and 2±1%, respectively. “Little” prolactin was much less in proportion after administration of bromocriptine. These results indicate that prolactin molecules in the tumor parenchyma leaks into the CSF, and that there would be different mechanisms of bromocriptine in reducing prolactin level in both serum and CSF among individual cases. Large molecular prolactin may arise as a derivative or aggregates of standard prolactin.
