In studying the problem of the peculiar susceptibility of the kidney to coliform bacterial infection it was found that kidney tissue, unlike that of other organs, interferes with the ability of normal serum to destroy these organisms.
The effect was attributable to strong anticomplementary activity, 5 to 15 times greater than that of other organs. Inactivation of complement by kidney tissue was found to have characteristics of a chemical reaction, the active principle being heat-labile, non-dialysable, and difficult to separate from tissue particles. Attempts to purify it or to obtain it in a soluble form usually resulted in great loss in activity.
The component of complement affected was the fourth; i.e., that which is characterized by susceptibility to injury by ammonia. Similarities were found to exist between the conditions of ammonia formation and complement inactivation by kidney homogenates, the most notable being enhancement by phosphate and glutamine.
The possibility is suggested that these findings may help to explain the vulnerability of the kidney to certain infections, especially those due to bacteria which are destroyed by the combined action of complement and antibody.
