Table 1. The effect of antioxidants and respiratory chain inhibitors on calcium influx in C2C12 cells.

Calcium influx in C2C12 cells	Mean±s.e.m.	P-value
Addition of antioxidants
10 μM doxorubicin	1.97±0.14
10 μM doxorubicin+1 mM trolox	2.40±0.45	0.2
10 μM doxorubicin+0.5 mM trolox	2.11±0.14	0.5
10 μM doxorubicin+0.1 mM trolox	2.43±0.11	0.2
10 μM doxorubicin+10 μM trolox	2.13±0.44	0.6
10 μM doxorubicin+1 mM N-acetyl cysteine	1.95±0.18	1.0
10 μM doxorubicin+0.1 mM N-acetyl cysteine	2.10±0.10	0.7
10 μM doxorubicin+10 μM N-acetyl cysteine	1.84±0.36	0.7

Addition of respiratory chain inhibitors	Mean±s.e.m.	P-value
10 μM rotenone	0.81±0.15	0.001
0.1 μM rotenone	0.69±0.08	0.000
25 μM piericidin A	0.92±0.23	0.001
2.5 μM piericidin A	0.74±0.03	0.000
0.25 μM piericidin A	0.91±0.10	0.001

Data are expressed relative to control values without doxorubicin (DOX). P-values are expressed as compared with values with 10 μM DOX present. None of the antioxidants added resulted in a significant decrease in DOX-induced calcium influx (no significant difference with DOX alone). None of the respiratory chain inhibitors resulted in an increase in calcium influx (all values below 1). Therefore, all the values were significantly different from incubations with 10 μM DOX.