Intracellular and intercellular distributions of acid kininogenases in spleen

Intracellular distributions of acid kininogenases were investigated following the subcellular fractionation of bovine and rat spleens. Acid kininogenases as well as other acid hydrolases were observed to be distributed in several fractions. Relatively high kinin forming activity was found in two fractions which were considered to contain lysosomes from reticulum cells and from lymphocytes respectively. The latter fraction had shown the higher sensitivity to thiol compound for its activation. These findings led us to the separation of the free cells existing in spleen each other. We adopted the techniques such as Ficoll-Isopaque centrifugation, plastic dish treatment and iron carbonyl treatment for this purpose. Lymphocyte from rat thymus was also examined and proved to have acid kininogenase activity as well.