A STUDY OF THE ANTIBODIES PRODUCED IN RESPONSE TO PURIFIED PREPARATIONS OF SHEEP INTERSTITIAL CELL STIMULATING HORMONE

Abstract

SUMMARY 1. The antibodies produced in rabbits in response to purified preparations of sheep interstitial cell stimulating hormone (ICSH) have been studied by the Ouchterlony technique for the analysis of precipitins. It has been possible to identify the ICSH precipitin in vitro. 2. The antibody to sheep ICSH forms precipitin bands with sheep ICSH and with ox ICSH, but not with hog ICSH or with human chorionic gonadotrophin (HCG). 3. Antiserum to sheep ICSH, absorbed so that a single demonstrable antibody is present, inhibits the biological effect of sheep and of ox ICSH but not of hog ICSH or of HCG. This antiserum did not interfere with the action of endogenous rat ICSH. 4. There was no cross-reaction demonstrable between the sheep ICSH antigen-antibody system and the pneumococcus polysaccharide type XIV system as has been reported for the antigen-antibody system of HCG. 5. Two attempts to repeat the method of Takeda, Otsuka & Noda [1952] for the preparation of crystalline ox ICSH were unsuccessful.