Mechanisms of Anthracycline-Enhanced Reactive Oxygen Metabolism in Tumor Cells

Table 1

Kinetic constants for superoxide production by Ehrlich tumor subcellular fractions after treatment with doxorubicin. Superoxide production by tumor microsomes, mitochondria, and nuclei was assayed as described in Tables 2, 6, and 7. Kinetic constants were determined in triplicate to form the direct equation relating reaction velocity to substrate concentration as described in [48] using 8 different drug concentrations over a 10-fold concentration range.

Subcellular fraction	Superoxide formation
	(μM)	(nmol/min/mg)
Microsomes	124.9	22.6
Mitochondria	123.2	14.7
Nuclei	103.4	4.8