Effect of endotoxin from Serratia marcescens on the permeability of vessels in hepatomas and carrageenin granulomas of rats.

polysaccharide (endotoxin) was injected i.v. into rats bearing carrageenin-induced granulomas and transplanted hepatomas, and the vascular-permeability changes were studied by injecting Pelikan ink i.v. at various times after the endotoxin (or saline in the controls). When the ink was given at 0 or 1 hr. there was little difference between the treated rats and the controls. But when the ink was given 2 or more hr. after the endotoxin there was a marked increase of the carbon-lined capillaries and venules, compared with controls, in tumour, granuloma, glomeruli, adrenal cortex, lung, lymph-nodes and sometimes heart. The significance of these changes is discussed in relation to the Shwartzman phenomenon, Arthus reaction, and adrenaline-induced vascular spasm producing anoxia.