Stimulation of glucose utilization and glycosaminoglycans production by fibroblasts derived from retrobulbar tissue

Abstract

Cultures of fibroblasts derived from human retrobulbar tissue responded to the presence of living lymphocytes with increased release of glycosaminoglycans to the media and accelerated glucose utilization. At times the fibroblast proliferation rate was enhanced by the lymphocytes, but the metabolic changes were out of proportion to the changes in fibroblast number.Normal ranges of responses in glycosaminoglycan production and glucose utilization by the cultures were defined for the addition of lymphocytes, at two dose levels, from 19 normal subjects.Unpurified leukocytes were more potent stimulators of these cultures than were lymphocytes, but the latter were obtained in almost pure form and clearly contained the stimulating properties under investigation. Erythrocytes and platelets were devoid of activity in this system. Freeze-thawed lymphocytes contained activity, but this was found only after 24 hr of preincubation and quantitatively was much less predictable than that in the living lymphocytes. Hyaluronic acid comprised nearly all, if not all, the media glycosaminoglycans in both stimulated and nonstimulated cultures. No metachromasia was detected in the fibroblasts after they were stained with toluidine blue-0, which suggests that the stimulating mechanism(s) did not augment the intracellular glycosaminoglycans of the cultures.