Abstract
It is a well known fact that systemic scleroderma is a disorder of the connective tissue, and previous reports noticed an increase in collagen synthesis in the patients. This report describes investigation of skin collagen synthetic activity in patients with systemic scleroderma and in mice with experimental scleroderma which was induced with the scleroderma-inducing glycosaminoglycan isolated from the urine of patients with systemic scleroderma. Skin biopsies were taken from 20 patients with systemic scleroderma from forearm or back, and histologically classified, after the description of Ishikawa, into stage I (clinically uninvolved), II (moderately involved), and III (markedly involved).
Collagen synthetic activity was determined by incubating sliced biopsy specimens in a medium containing radioactive proline, and the radioactivity of synthesized hydroxyproline was measured by the method of Juva-Prockop.
As the result, it was found that skin collagen synthetic activity of the patients did not increase in the skin of stage I, relatively increased in stage II, and was unchanged or rather decreased in stage III, as compared to normal controls at the corresponding sites. Furthermore, in accordance with this result, some mice injected with the scleroderma-inducing glycosaminoglycan displayed high skin collagen synthetic activity with histologically slight sclerodermatous skin change or without definite skin change, while others showing marked sclerotic change did not demonstrate an increase in collagen synthetic activity. In summary, the present study indicates that increase in collagen synthesis in systemic scleroderma is rather of a minor grade.
