Recently interest in diseases which may result from specific antibodies acting in vivo has been intensified by the following observations: It has been demonstrated that injection of animals with antiserum prepared from homologous kidney results in progressive renal lesions (1-5). Glomerulonephritis in rats has resulted also from the action of autoantibodies following the injection of rat kidney mixed with killed streptococci (6). Furthermore, in man it has been established by the work on erythroblastosis foetalis (7) that specific cytotoxic antibodies may arise naturally and cause serious or fatal disease.The clinical picture of the toxemias of pregnancy has many points in common with acute glomerulonephritis; namely, the explosive development of albuminutia, cylindruria, olignria, and hypertension. There has long been speculation about the possible r61e of the placenta in the etiology of the toxemias. This organ, derived in part from the fertilized ovum, suggests an obvious source of antigen which might prove foreign to the mother and provoke the production of injurious antibodies. With the idea in mind to test the possible renal effect of such an antigen-antibody reaction, a series of experiments was undertaken in which rabbit anti-rat-placenta serum was injected into pregnant rats. Specific anti-placenta serum has been known to interrupt pregnancy in the guinea pig and rabbit since the observations of Dobrowolski in 1903 (8). Degeneration of the placentae and fetal death likewise were found to follow the injection of rabbit anti-rat-placenta serum in rats of the Long-Evans strain (9). However, no acute renal lesions were observed at autopsy in these animals which were sacrificed at term 9 days after the antiserum was given.Smadel and Swift (10) reported that rats of the Long-Evans strain injected with nephrotoxic serum, may require months to develop chronic glomerulonephritis. It therefore seemed of interest to allow animals injected with antiplacenta serum to remain under observation for a period of months in order to detect a possible eventual effect on the kidneys. The present paper reports these experiments controlled by studies on additional groups of rats which were injected with anti-rat-kidney serum, anti-rat-erythrocyte serum, antirat-serum serum, normal rabbit serum, or which were left untreated. A preliminary description of some of these results has already appeared (11,12). 211

The first of the three experiments reported herewith was undertaken to compare the relative capacities of cortisone acetate and desoxycorticosterone acetate (DCA) in maintaining the adrenalectomized rat on a sodium-restricted regimen. The most striking finding in the course of observation was the development of marked hypertension in the cortisone acetat~injected animals in contrast with the rats treated with DCA, which remained normotensive. Because of this unexpected finding, observations were extended in Experiment 2 to include comparisons of these two steroids in adrenalectomized rats of another sex and source and on a high sodium regimen as well as on a sodiumrestricted one. The hypertensive effect of cortisone acetate in the latter group was confirmed. Experiment 3 was added to study the effects of cortisone acetate and D C A in intact as well as in adrenalectomized rats, on both high and low sodium regimens.Incidentally to the effects of the two steroids on blood pressure, observations on body and organ weights, serum electrolytes, and histological findings are reported. Experiment 1Procedure:--