[Inhibitory effect of clonidine on hemolysis after thermal injury in animals].

Clonidine (1 mg.kg-1, ip) inhibited hemolysis in mice and rats after burn. The effects were abolished by pretreatment with yohimbine (5 mg.kg-1, ip) but not by prazosin (10 mg.kg-1, ip). The increased osmotic fragility of erythrocytes and the elevation of plasma NE level in burned animals were markedly lowered by clonidine which also raised the glutathione level of whole blood and enhanced the activity of glutathione peroxidase. These results indicated that the action of clonidine on hemolysis was carried out by means of depression of adrenergic alpha 2 receptors and reduction of free radicals.