Effect of oxidized cholesterol on age-associated changes to immune parameters in spleen lymphocytes and peritoneal exudate cells derived from rats

The effects of oxidized cholesterol on immune parameters were examined by u sing spleen lymphocytes and peritoneal exudate cells (PEC) derived from 5-w eek- (Young) and 9-month-old (Adult) rats. The immunoglobulin (Ig) G and Ig M production was inhibited by oxidized cholesterol in the rats of both ages when lymphocytes were exposed to 30 mu g/ml of oxidized cholesterol for 24 hr. The intracellular IBA level was also lowered by 30 mu g/ml of oxidized cholesterol, irrespective of age. In contrast, IgE production was signific antly increased by the addition of 30 mu g/ml of oxidized cholesterol in on ly young lymphocytes. Moreover, oxidized cholesterol enhanced the intracell ular histamine accumulation in only adult PEC, although the total histamine level produced by PEC was similar in the rats of both ages. These results thus suggest the possibility that oxidized cholesterol can have different e ffects on the age-related modulation of immune functions such as Igs produc tion and histamine release.