Influence of vitamin A on immunological response.

The influence of vitamin A injections on immunological response in mice was investigated. Two end-points were used: the titre of haemagglutinin at 10 or 15 days after sensitization with sheep red blood cells (SRBC), and the time to reject C57BL/6 male skin grafts by isologous female recipients. Daily vitamin A injections for the 5 days preceding or following sensitization with SRBC led to a large increase in the production of haemagglutinin antibodies. Injection of vitamin A for the 5 days preceding or following grafting, or starting on the 6th day after grafting, significantly reduced the mean rejection time of male skin grafts.