Identification of two classes of prolactin-releasing factors in XXXX from @entity19 .

@entity398 @entity4089 @entity11982 @entity4059 @entity19 @entity5 @entity2235 @entity1313 @entity1218
Targeted tumorigenesis, using the @entity11982 gene promoter ligated to the @entity2235 large T antigen, generated @entity19 with massive @entity5 of the intermediate lobe (IL) of the pituitary. Inoculation of @entity19 with the IL @entity5 cells resulted in very large secondary @entity5 . As the IL from several species produces a potent @entity4059 ( @entity4059 ), it was of interest to determine whether @entity1313 from these @entity19 also contain @entity4059 . The objectives were to 1) measure serum PRL levels in @entity19 with @entity1313 , 2) determine whether these @entity5 contain @entity4059 and examine its chromatographic properties, and 3) analyze whether this @entity4059 is related to @entity11982 , its derivatives, or other PRL secretagogues. Serum PRL levels were 5- to 6-fold higher in transgenic than in control @entity19 . Primary and secondary @entity1313 were acid extracted and successively fractionated using Sephadex G-100 gel filtration and reverse phase and gel permeation HPLC. @entity4059 activity was determined using short term incubation of tissue extracts or column fractions with GH3 cells. Crude @entity5 extracts exhibited a strong and dose-dependent @entity4059 activity. Upon chromatography, the @entity4059 activity from either primary or secondary @entity5 resolved into two classes of compounds: a big @entity4059 with an estimated mol wt of 70-80 kilodaltons and two small, very hydrophobic peptides. The elution profiles of the three PRFs differed from those of beta-endorphin, alpha MSH, @entity11982 , ACTH, @entity1218 , @entity398 , angiotensin II, vasoactive intestinal polypeptide, or corticotropin-like intermediate peptide. In summary, we have identified an animal model with @entity1313 that has @entity4089 and overproduces @entity4059 . Two classes of PRFs, big and small, were resolved which differ from @entity11982 derivatives and known regulators of PRL release. These data suggest that @entity4059 is produced by melanotrophs, but is not a product of the @entity11982 gene. The @entity1313 should provide an excellent source for the purification and structural elucidation of PRFs.
