IMMUNOCYTOCHEMICAL APPROACH TO THE STRUCTURE OF HUMAN BLOOD GROUP-B AND GROUP-H GLYCOCONJUGATE ANTIGENS IN THE 3 DAYS OLD RAT COCHLEA

The possible structure of human blood-group antigens, as found in coch lear hair cells of 3-day-old rats, is suggested. Data were obtained fr om immunocytochemical studies using 77 antibodies against the major hu man blood group antigens of the ABO, H, I and Lewis genetic systems. N either the anti-A-related nor the anti-Lewis-related antibodies showed any positive immunoreaction on hair cells. In contrast, anti-B, anti- AB and anti-H antibodies displayed specific positive immunoreactive pa tterns on the hair cells. The results suggest that, in immature hair c ells, two main glycoconjugate structures of the lactoseries are presen t: H type 2 antigen, which is the precursor of the B type 2 antigen, a nd the B type 2 antigen itself. Similar H and B carbohydrate structure s have been reported in rat olfactory receptors. The type 2 glycoconju gates carrying these H and B antigens of auditive and olfactory recept ors are resistant to fixation and paraffin embedding, suggesting that they might be glycoproteins. These auditive and olfactory H and B anti gens must be different from the B-related antigens that are expressed by pseudo-unipolar neurons of rat posterior root ganglia, that are bui lt from type 4 core chains, and that are destroyed by routine paraffin embedding procedures.