Prolactin, Immunologic Evidence of Species Specificity.

Abstract

The immunological relation between ovine and human prolactin was investigated. Antiserum was produced by injecting either an ovine or a human prolactin prepreparation, in Freund''s adjuvant, into rabbits. The resulting antisera were evaluated by the hemagglutination technique and by diffusion studies in semi-solid media. Both hormone preparations produced antibodies that reacted with the homologous antigen; neither antiserum cross-reacted with the heterologous hormone preparation. Nor did the anti-ovine prolactin antiserum react with an extract of mammatrophic tumor extract. Diffusion studies showed 1 precipitation band in the ovine-anti-ovine prolactin reaction, and 2 bands in the human-anti-human system; one of these latter bands disappeared after absorption of the serum with human growth hormone. Inter-species precipitation bands were absent. These findings support the species specificity of prolactin.