SIZE HETEROGENEITY OF HUMAN PROLACTIN IN CSF AND SERUM - EXPERIMENTAL CONDITIONS THAT ALTER GEL-FILTRATION PATTERNS

Cerebrospinal fluid (CSF) and sera of hyperprolactinemic patients with pituitary tumors were chromatographed on a Sephadex G-100 column. Three PRL peaks were found in serum and CSF that were immunologically similar to the pituitary PRL standard. The percentage of PRL in peak 1, near the void volume, was significantly (P< 0.05) greater in CSF than in serum. The elution pattern observed in serum was not changed by treatment of the pituitary tumor patients with hypophysectomy or radiation therapy, although serum PRL levels uniformly decreased. Sera from normal women obtained during sleep demonstrated elution patterns similar to those found in the sera of pituitary tumor patients; however, the percentage of PRL in peak 1 was significantly (P < 0.05) greater in the normal women. Incubation of pituitary PRL for 4 h in hypoprolactinemic serum and normal CSF before elution did not change its gel filtration pattern when compared to elution with column buffer alone. Serum PRL gel filtration patterns were stable when subjected to multiple freeze-thaws, whereas this treatment of CSF resulted in dramatic increases in peak 1 accompanied by a decrease in peak 2 and peak 3. The elution patterns of the same serum sample chromatographed at 4 C and 23 C differed in that the percentage of peak 1 PRL was significantly (P< 0.01) greater at 4 C than at 23 C. Hence, a variety of in vivo and in vitro experimental conditions can influence the elution profile of serum and CSF prolactin. © 1978 by The Endocrine Society.