GLUCOSE-6-PHOSPHATASE HISTOCHEMISTRY OF OSTEOARTHRITIS

A cytochemical study of glucose-6-phosphatase (G-6-Pase) was made to s ee the changes in mucopolysaccharide metabolism in the synovial membra ne during osteoarthritis, because the tissue is thought to play an imp ortant role in synovial fluid production by providing lubrication to t he wear-and-tear surface of the synovial cartilage in osteoarthritis, In normal and osteoarthritic synovial membranes, a high G-6-Pase activ ity was clearly demonstrated in the cisternal spaces of the rough endo plasmic reticula, especially in the B cells of the thickened synovial membrane. The existence of an AB cells intermediate in character betwe en A and B, was noted in having a high G-6-Pase activity in the accumu lated rough endoplasmic reticula in the cytoplasm as B cells do locate d at the deeper part of the membrane, but also whose cell surface exte nds to the top of the membrane surface reaching into the synovial cavi ty, and protrude microvilli of a ruffled border indicating a high phag ocytotic activity as A cells do. The existence of the AB cell is clear ly one of intermediate structure and function, contributive to the com pensatory and regenerative action of the synovial membrane.