Effect of Adrenergic Drugs on the Lipopolysaccharide-Induced Oxidative Stress and Liver Damage in the Rat

Aim: We aimed to investigate the effect of the adrenergic system on oxidative stress and liver damage during mild systemic inflammation in rats. Methods: For this purpose, Eschrechia coli lipopolysacchride (LPS; 300μg/kg) was intraperitoneally injected either alone or along with the α-2 adrenoceptor antagonist yohimbine, the non-selective β adrenoceptor antagonist propranolol, the and β-adrenoceptor agonist adrenaline and rats euthanized 4h later. The effects of these drugs in saline-treated rats were also studied. Serum alanine aminotransferase (ALT), aspartate aminotransferase, and alkaline phosphatase activities were measured. Liver tissue levels of malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH) were determined and liver histology evaluated. Results: In saline-treated rats (i) yohimbine caused significantly increased ALT, AST and ALP in serum. In addition, yohimbine increased MDA, NO and decreased GSH in liver tissue and caused cytoplasmic vacuolations and cellular infiltration: (ii) adrenaline treatment increased serum ALT, AST, liver MDA, decreased liver GSH and caused minute vacuolar degeneration and foci of necrosis; (iii) in contrast, there were no biochemical or histologic alterations after propranolol treatment. In endotoxaemic rats; (i) serum aminotransferases and alkaline phosphatase were significantly increased by yohimbine together with increased liver MDA, NO and decreased GSH content; (ii) serum ALT decreased by propranolol and adrenaline while serum ALP increased by adrenaline; (iii) liver GSH increased by propranolol; (iv) LPS administration caused acute liver damage in the form of foci of necrosis, vacuolar degeneration and aggregates of inflammatory cellular infiltration. Compared with the LPS only group, treatment with yohimbine increased while propranolol or adrenaline produced less liver damage. Conclusions: Thus, blockade of α-2 adrenoceptors increased while β adrenoceptor antagonism decreased oxidative stress and liver damage following LPS administration in rats. Collectively, these results indicate a benefit from blockade of beta-adrenoceptors in protecting the liver during mild systemic inflammation in part by decreasing oxidative stress.