Up-regulation of avian uncoupling protein in cold-acclimated and hyperthyroid ducklings prevents reactive oxygen species production by skeletal muscle mitochondria

Table 2 Activities of cytochrome-c oxidase and antioxidant enzymes in skeletal muscle.

Enzymes	Hypo	TN	CA	T₃
COX	8 ± 2 *	31 ± 4	35 ± 5	23 ± 3
SOD
total	1164 ± 112 *	2134 ± 222	2039 ± 250	1506 ± 114 *
Mn	729 ± 59 *	1048 ± 115	1011 ± 88	956 ± 121
Cu,Zn	435 ± 151 *	1086 ± 204	1028 ± 279	550 ± 121 *
GPX	1.17 ± 0.13	1.39 ± 0.22	1.56 ± 0.16	1.60 ± 0.16

Enzyme activities were measured in red gastrocnemius muscle from thermoneutral control, cold-acclimated, hypothyroid or T₃-treated ducklings. Cytochrome-c oxidase (COX) was measured polarographically in tissue homogenates. Superoxide dismutase and glutathione peroxidase were measured spectrophotometrically in tissue homogenates.

ISSN: 1472-6793