Plasma Corticosterone Level in Runt Disease

In rats with runt disease, spleen cell transfer raised initially the plasma corticosterone level, but it decreased to subnormal level the 2d day. Thereafter, the increase again became evident and remained almost twice that of intralitter control rats. It varied from 22.4–40.9 μg/100 ml. These high levels were generally associated with intensity of clinical symptoms. Of rats with runt disease, 100% (11/11), 98% (11/12), and 100% (18/18) had elevated plasma corticosterone levels 7,11, and 25 days after cellular transfer, respectively. After 26 days, the plasma corticosterone level declined to normal range. These results show that runt disease, induced by injection of parental spleen cells into rats, had a biphasic pattern of corticosterone secretion. These elevated levels resulted from “immunological stress” by cellular transfer in the initial stage, but aggravated the process of runt disease at the terminal stage.