Cyclic nucleotides and calcium transport in cultured dermal fibroblasts from progressive systemic sclerosis and rheumatoid arthritis patients.

Levels of cAMP were decreased and cGMP increased in progressive systemic sclerosis (PSS) fibroblasts compared with normal fibroblasts. PSS cells took up unusually large quantities of Ca++. The epinephrine-induced increases in cAMP were diminished sixfold and epinephrine-induced Ca++ uptake was abnormal in PSS cells. Considerable heterogeneity was observed in rheumatoid arthritis fibroblasts. Membrane-bound abnormalities in (PSS) cells may be of importance in the defective control of collagen production in progressive systemic sclerosis.