Radioimmunological dosage of human prolactin

The radioimmunological dosage of human prolactin using the hormone as tracer and reference and an anti-prolactin antiserum is described. The labelling of human prolactin is carried out in the presence of a small quanitity of chloraminet (10 ug). The purification of the labelled hormone is carried out by gel filtration on sephadex G-75 by polyacrylamide gel electrophoresis. The optimal incubation conditions were found using a first incubation of 40-48 hours at room temperature followed by one of 4 to 6 hours with cellulosebound second antibody. The interference of serum proteins is small. There is no cross-reaction with follicle stimulating hormone (FSH), luteinizing hormone (LH), tyroid stimulating hormone (FSH), human chorionic gonadotrophin (HCG), human placental lactogen (HPL) and human growth hormone (HGH). However, cross-reaction with ovine, bovine and rat prolactin is found. These cross-reactions are complete with endogenous human prolactin and hormone of different origin. Serum prolactin was determined in normal subjects and subjects treated with TRH and bromoergocryptine. (G.C.)