Studies on the Effects of Corticosteroid and ACTH on the Blood and Bone Marrow Pictures.

Part. Results Obtained in Rabbits Previously Treated with Mitomycin C

Abstract

Rabbits with bone marrow depression caused by Mitomycin C (MMC) (2 mg i. v., twice at a 2 week interval) were treated intramuscularly for five days with β-Methasone (βM) (2 mg/kg/day) or ACTH (8.3 units/kg/day). The treatment began from the fourth day after the second injection of MMC. The hemoglobin content are the red cell, leucocyte, neutrophil, and lymphocyte counts all decreased after the second MMC injection. The blood and bone marrow pictures of these rabbits (M group) during or after the hormone treatment were serially examined and compared with the findings in normal rabbits (N group) treated with the hormones.
The results obtained were as follows
1) In both groups, the RCC decreased during treatment and increased after discontinuance: The increased counts recovered their normal levels quicker in the M group than in the N group. In both groups, the CI and MCD were similarly increased by,βM and decreased by ACTH.
2) In both groups, the WCC and NC temporarily rose followed by a descent with either hormone, the grade of the descent being more remarkable in the M group th a n in the N group.
3) Concerning the bone marrow picture, the erythroid cell count increased in the N group and the ACTH-treated M group. After the discontinuance of treatment, thi s cell count returned to normal in the N group, but in the ACTH-treated M group, t he count remained elevated. In both groups, the myeloid cell count was decreased by either hormone; the N group returned to normal after discontinuance, but the M group still maintained its low myeloid cell count.