Abstract
Basal intracellular cAMP levels of lymphocytes from patients with systemic sclerosis, all suffering from Raynaud's phenomenon, were significantly lower than those obtained from normal controls. Moreover, the cAMP response to isoprenaline of these patients' lymphocytes was inhibited. Intravenous infusion of prostaglandins (E1 and I2) restored the basal levels and greatly improved the responsiveness of the cells to isoprenaline stimulation.