Pretibial myxoedema: stimulation of mucopolysaccharide production of fibroblasts by serum.

We have shown that sera from normal individuals and from patients with pretibial myxoedema contain a factor which simulates mucopolysaccharide biosynthesis in normal human skin fibroblasts cultured in vitro. This factor was present in larger amounts in sera of patients with pretibial myxoedema. The role of growth stimulating factors in serum is reviewed and a hypothesis is put forward that the fibroblast stimulating factor is somatomedin and that its presence in increased amounts in thyroid disease may lead to pretibial myxoedema.