Changes in the growth and metabolism of cells cultured from normal, sclerotic and rheumatoid connective tissue brought about by D-penicillamine and by sodium salicylate.

D-penicillamine and sodium salicylate were equally effective in suppressing the proliferation of fibroblasts from normal and scleroderma skin and rheumatoid synovial cells. The effects were concentration-dependent, beginning at around 100 microgram/ml, and proliferation was almost halted at 1600 microgram/ml. Individual cell strains of each type showed differences in drug susceptibility but there was no consistent difference between cells from normal and abnormal tissues. Acid mucopolysaccharide secretion was more clearly inhibited in scleroderma fibroblasts than in synovial cells, and penicillamine produced greater inhibition than salicylate, beginning at 10 microgram/ml and reaching almost 50% at 500 microgram/ml. Confluent cultures of scleroderma fibroblasts showed 23% less incorporation of 3H-proline into collagenase-sensitive protein in the presence of 1600 microgram/ml penicillamine, without significant effect on other protein synthesis; sodium salicylate had no effect. These data suggest that D-penicillamine may affect connective tissue metabolism in other ways than by interfering with collagen synthesis or cross-linking.