Intensification of Doxorubicin-Related Oxidative Stress in the Heart by Hypothyroidism Is Not Related to the Expression of Cytochrome P450 NADPH-Reductase and Inducible Nitric Oxide Synthase, As Well As Activity of Xanthine Oxidase

Table 6

Xanthine oxidase activity (μU/g of cardiac sample; 𝑋±S.D.) in rat cardiac homogenates 4, 48, and 96 h after doxorubicin administration.

Time from DOX injection (h)	Dose of DOX (mg/kg b.w.)	Methimazole			ANOVA
		0.0000	0.001%	0.025%	𝑃
4	2	52.00±14.00	56.00±17.10	47.00±18.00	0.6229
	5	43.00±8.00	43.00±14.50	47.00±18.60	0.9680
	15	57.00±8.00	34.00±2.90^*,#	101.00±6.91^#,†	0.0171
48	2	38.00±17.10	56.00±14.30	54.00±16.60	0.1998
	5	34.00±10.60	66.00±50.00	64.00±17.4	0.0602
	15	65.00±37.00	54.00±9.40	58.00±15.7	0.9324
96	2	50.00±16.80	67.00±19.00	55.00±24.6	0.3705
	5	54.00±32.70	60.00±10.90	49.00±18.00	0.3724
	15	68.00±33.60	52.00±7.10	60.00±12.60	0.6057
	0.9% NaCl	𝟕𝟎.𝟎𝟎±𝟑𝟓.𝟖𝟎 (control)	52.00±10.70	46.00±6.60

^*𝑃<0.05 versus control; ^#DOX + MET versus DOX; ^†DOX + MET_H versus DOX + MET_L.