Response kinetics of host and experimental solid tumour after adriamycin.

The effects of adriamycin (Adr) on the solid-tumour model, hepatoma 3924A, and on critical organs of the host, were determined at intervals after single injections of 60 mg/m2 of the agent. A reduced rate of tumour growth was evident 4 days after treatment, continued to Day 11, and then returned to rates comparable to control values. On Day 11 tumour volumes of treated animals were 38% of control. During the period of reduced growth, 3H-TdR incorporation into tumour DNA and percentage labelled tumour cells were less than control values. DNA concentration in tumour was not affected by drug treatment, which differs from observations made in other studies employing 5-fluorouracil (FU). No evidence of significantly increased necrosis or fibrosis of the tumour was found after Adr. The Adr treatment caused loss of 60% of the tibial marrow by Day 4, as measured by total DNA content. Marrow DNA recovered to control levels between Days 7 and 11. Incorporation of 3H-TdR into heart DNA was reduced more than 40% during the first week after Adr treatment; enhanced incorporation was observed on Day 11, and control levels were attained by Day 17. No significant pathological evidence of cardiac toxicity was found 2-21 days after Adr but degeneration of myocardial cells and oedema was prominent at 14 weeks.