The H, HI, I and i blood group antigens in butanol extracts of rabbit tissues.

Aqueous and butanol phase extracts of rabbit erythrocytes and the tissues gastric mucosa, liver, lung and kidney were examined by inhibition of agglutination for the presence of H, HI, I and i blood group substances. Of the four specificities, only I substance was recovered from erythrocytes and only in the aqueous phase extracts. Both aqueous and butanol extracts of gastric mucosae contained H substance, but HI and I were present only in the aqueous extracts of this tissue. Extracts of rabbit lungs only had H and I activity and only in the aqueous phase. No H, HI, I or i substance was detected in any of the extracts of liver and kidney. Reduced levels of H substance were found in aqueous extracts of gastric mucosae of 'A-like' rabbits. Three H specificities were demonstrated in the butanol phase extracts of gastric mucosae of rabbits. These specificities were similar to those previously shown in extracts of gastric mucosae and erythrocytes of humans.