A Test of Connective Tissue State and Reactivity in Collagen Diseases*

In the group of conditions known as diseases there are often morphological changes in discrete areas of the connective tissue. For example, fibrinoid degeneration of the collagen fibers and changes in the ground substance may be seen in the subcutaneous nodules of rheumatoid arthritis and in the skin lesions of lupus erythematosus. These lesions are not well understood. The more generalized alterations in the connective tissue are even more difficult to demonstrate and remain poorly defined. Using an in vivo electrometric method, we have previously determined certain physicochemical properties of normal mammalian connective tissue which are related to its amphoteric colloidal structure (1-5). Since these properties may be altered in pathological states, we have adapted this method to study some of the