EFFECT OF RADIATION AND AGE ON IMMUNOGLOBULIN LEVELS IN RHESUS-MONKEYS (MACACA-MULATTA)

We report the results of a study on the immunoglobulin levels of rhesu s monkeys (Macaca mulatta) in a colony consisting of the survivors of monkeys that received a single whole-body exposure to protons, electro ns or X rays between 1964 and 1969. This colony has been maintained to assess the long-term effects of ionizing radiation on astronauts and high-flying pilots. Of the original 358 monkeys that were retained for lifetime studies, 129 (97 irradiated and 32 controls) were available for our study. We found no significant difference between the irradiat ed and control monkeys in mean levels of IgA, IgG and IgM, irrespectiv e of the radiation treatment. The availability of these aged monkeys p rovided a unique opportunity to compare their immunoglobulin levels to those of other monkeys of various ages, and thus assess the effect of age on immunoglobulin levels. We found that only the IgA levels incre ase with age.