The use of anti-cartilage antisera in the study of human spleen.

Antisera against human hyaline cartilage, particularly antisera against collagenase-treated residue obtained after extraction of cartilage homogenate with 3.4 mol dm-3 NaCl and extraction with 0.05 mol dm-3 sodium citrate buffer at pH = 3.2, reacted with different fibrillary and membraneous structures of the human spleen. Very intensive immunofluorescence was observed in special spongiform structures at the end of the arterial system, referred to as spongy arterial terminals. Fibrillary and membraneous structures situated perivascularly, in lymphatic sheaths and the periphery of follicles displayed similar reactions. The discontinuous walls of sinuses and reticular fibrils in pulp cords reacted less intensively. The given antisera are used to advantage as immunohistologic reagents since they clearly visualize the basic structure, and particularly the spongy arterial terminals, otherwise inconspicuous. In the hyaline cartilage of the rib and knee, the cartilage channels yielded the most intensive reaction. Of the other organs studied the marked reaction in the mesangium of the renal glomerulus was the most remarkable.