Abstract

Administration of ovine growth hormone to young C3Hf mice inhibited Gross passage A virus-induced leukemogenesis as manifested by a delayed onset and a lower incidence of thymus leukemia. These results can be interpreted that growth hormone inhibited thymus-dependent leukemogenesis perhaps through thymotrophic influences which prevented or delayed the thymus involution believed to be essential for leukemia change. In female but not in male Gross passage A virus-infected mice, development of a thymus-independent leukemia appeared to be promoted by growth hormone. 1 This work was supported by Grant DRG-1224 from the Damon Runyon-Walter Winchell Cancer Foundation and by NIH Grant Al12507. 2 To whom requests for reprints should be addressed.