Nature of the Renal Lesions induced by Intravenous Injection of Carrageenan

Abstract

CARRAGEENAN, a sulphated polygalactose extracted from several seaweeds, has many interesting biological properties. Injected subcutaneously it produces a granuloma in guinea pigs, rats, and rabbits¹. It inhibits several proteases² and exerts some action on serum lipids^3,4. The toxic effect of intravenously injected carrageenan was also noted⁵. We observed a strong inhibition of serum complement by carrageenan in vivo and in vitro⁶ and this observation prompted us to undertake a detailed examination of its action on guinea pigs, rats and rabbits after intravenous injection. Crude carrageenan (from Marine Colloids Inc., New Bedford, Mass, (we thank Mr. Stoloff for kindly sending a sample of carrageenan)) was dissolved in sterile saline shortly before injection. A 1 per cent solution was prepared and injected in the marginal ear vein of rabbits (2.5–3 kg) and in the penis vein of rats and guinea pigs. Venous blood was taken 3–4 times a day for the determination of serum complement by the 50 per cent hæmolysis technique of Roulier⁷, total serum proteins by a biuret method, blood urea by a gasometric procedure and plasma fibrinogen by a gravimetric procedure after conversion to fibrin. Urine was also collected for the determination of total protein.