ANTIBODIES TO QUINOLINIC ACID AND THE DETERMINATION OF ITS CELLULAR-DISTRIBUTION WITHIN THE RAT IMMUNE-SYSTEM

Antibodies to quinolinic acid were produced in rabbits with protein-co njugated and gold particle-adsorbed quinolinic acid. Quinolinic acid i mmunoreactivity was below detection limits in carbodiimide-fixed rat b rain. In contrast, strong quinolinic acid immunoreactivity was observe d in spleen cells with variable, complex morphology located predominan tly in the periarterial lymphocyte sheaths. In the thymus, quinolinic acid immunoreactivity was observed in cells with variable morphology, located almost exclusively in the medulla. Lymph nodes and gut-associa ted lymphoid tissue contained many, strongly stained cells of similar complex morphology in perifollicular areas. Immunoreactivity in liver and lung was restricted to widely scattered, perivas cular cells and a lveolar cells respectively. Additional stained cells with complex morp hology were observed in bronchus-associated lymphoid tissue, in skin, and in the lamina propria of intestinal villi. Follicles in all second ary lymphoid organs were diffusely stained, ranging from mildly to mod erately immunoreactive in spleen, to intensely immunoreactive in gut-a ssociated lymphoid tissue. These results suggest that quinolinic acid is an immune system-specific molecule, Two hypothetical schemes are pr oposed to account for high levels of quinolinic acid in specific cells of the immune system.