Effect of Anticancer Quinones on Reactive Oxygen Production by Adult Rat Heart Myocytes

Table 3

Effect of oxygen radical modifiers on doxorubicin-enhanced, cyanide-resistant oxygen consumption by rat cardiac myocytes. Oxygen consumption was measured with a Clark-type electrode in a 3 ml reaction system at 37°C exactly as described in Table 2.

Reaction system	Oxygen consumption (percent of control)
Control	100^a
+Catalase (2500 units/ml)	^b
+Heat-inactivated catalase (2500 units/ml)^c
+Acetylated cytochrome c (50 μM)
+Dicumarol (50 μM)
Doxorubicin (400 μM)	100^d
+Catalase (2500 units/ml)	^e
+Heat-inactivated catalase (2500 units/ml)
+Acetylated cytochrome c (50 μM)	^e
+Dicumarol (50 μM)
+DTPA (100 μM)
+DMSO (100 mM)

^aControl rate of oxygen consumption was  nmol/min/ myocytes, . ^b of 3 to 5 experiments. ^cCatalase was inactivated by autoclaving for 60 min. ^dDoxorubicin-stimulated, cyanide-resistant oxygen consumption was  nmol/min/ cells, . ^eSignificantly different from samples containing doxorubicin alone, .