Oxidative Stress and Antioxidant Activity in Hypothermia and Rewarming: Can RONS Modulate the Beneficial Effects of Therapeutic Hypothermia?

Table 1

Oxidant/antioxidant status in rats after severe hypothermia and rewarming.

	Arterial Blood			Liver
	Sham	Hypothermia	Rewarming	Sham	Hypothermia	Rewarming
NOx	10.76±0.52	14.68±0.59^∗∗∗	12.57±0.48^∗,+	1.28±0.06	1.56±0.06^∗	2.00±0.10^∗∗∗,++
TBARS	3.60±0.10	4.66±0.36^∗	4.46±0.20^∗	3.93±0.36	4.32±0.43	3.30±0.31
GSH	221.02±5.53	230.61±8.24	140.42±7.50^∗∗∗,+++	4.56±0.37	4.50±0.17	2.91±0.17^∗∗∗,+++
SOD	100±3.58	82.86±1.95^∗∗	85.81±4.35^∗	100±3.11	102.80±3.59	100.80±5.73
GPx	100±3.09	101.94±3.38	57.41±7.28^∗∗∗,+++	100±2.91	99.54±6.87	92.27±2.16
CAT	100±7.54	71.45±4.39^∗∗	61.18±4.73^∗∗∗	100±5.34	90.50±6.22	90.34±2.90

Animals were assigned to 3 groups of 6 individuals each. Sham animals were killed after anesthesia. In hypothermia group anesthetized animals were cooled for one hour at a mean rate of −0.25°C /min to achieve 22°C. Then they were killed. The rewarming group was cooled as described above and then it was rewarmed at a rate of 0.35°C/min to 37°C. Oxidative indicators were the concentration of nitric oxide derivatives (NOx) in plasma (nM) and liver (nmol/mg protein) and thiobarbituric acid-reactive substances (TBARS) in plasma (nM) and liver (nmol/mg protein). Antioxidant status was evaluated as thiols in plasma (GSH, 𝜇M) and in liver (GSH, 𝜇mol/g liver). The enzymatic antioxidant activities of Cu-Zn superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were evaluated in erythrocytes and in liver and were expressed as a percentage of corresponding sham value. Data is mean ± SEM of six animals. Significantly different from corresponding sham values: ^∗𝑃<0.05, ^∗∗𝑃<0.01, and ^∗∗∗𝑃<0.001. Significantly different from corresponding hypothermia values: ⁺𝑃<0.05, ⁺⁺𝑃<0.01, and ⁺⁺⁺𝑃<0.001.