EFFECT OF CORTICOTROPIN ON CELLULARITY AND MITOSIS IN THE RAT BONE MARROW, SPLEEN AND THYMUS1

Abstract
Corticotropin gel in doses of 10 units/kg was given daily to tube fed adult rats and determinations made of the cellularity and mitosis in the bone marrow, spleen and thymus after 3, 10 and 20 days. The desoxyribonucleic acid phosphorus (DNAP) content of these organs was used as a measure of cellularity and the rate of incorporation of p32 into the DNAP as an index of mitosis. After 20 days the cellularity in the bone marrow was reduced to 65, the spleen to 33 and the thymus to 10% of the control values. Total mitotic activity was depressed to 75, 15 and 7% of the controls, respectively.