Gudzent and Schade’s Theories
Gudzent was of opinion that uric acid can only exist in the blood as the mono-sodium-urate, of which there are two isomeric varieties, the easily soluble unstable lactam, and the stable relatively insoluble lactim urate. It is the former, or lactam, variety that accumulates in the blood in gout and, according to Gudzent, it is the transmutation thereof into the lactim modification that determines the precipitation of urates in the tissues. The lactim urate is soluble only to the extent of 8·3 mg. per 100 cc. serum, whereas the lactam form is soluble up to 18 mg.
Others, like Bechhold, maintain that the urates are present in the blood in a colloidal form, impossible of excretion by the kidneys. Thus Schade contends that, in the presence of alkalies (hydrates), uric acid or its salts may pass into a state in which it is far more soluble than usual. Moreover, on its path to crystallisation from this over-saturated solution, it passes through a colloid stage in which it is relatively stable. The maintenance of this colloid stage and consequently the retardation of precipitation is promoted by certain substances, i.e., glycerine, urea, serum, albumen, nucleic acid, etc. But hitherto the therapeutic possibilities suggested have not been invoked.