Study of Protective Effects of β-blocker Carvedilol in Experimentally Induced Solar Burn
J. Nečas, L. Bartošíková, J. Petrželková, P. Kollár, H. Kotolová, V. Strnadová, P. Fráňa, L. Bartošová, L. Fráňa, J. Klusáková, J. Šalplachta
Acta Veterinaria Brno
Neãas J., L. Barto‰íková, J. PetrÏelková, P. Kollár, H. Kotolová, V. Strnadová, P. FráÀa, L. Barto‰ová, L. FráÀa, J. Klusáková, J. ·alplachta: Protective Effects of β-blocker Carvedilol by Experimentally Induced Solar Burn in Rats. Acta Vet. Brno 2001, 70: 397-401. Evidence that free oxygen radicals may be responsible for tissue damage following skin thermal injury supports a theory of interventional use of antioxidants in therapy. Carvedilol (CVD) is used for treatment of hypertension and
... ic heart failure. It also shows a potent scavenger property in pathological conditions in which free oxygen radicals (FOR) take part. We studied whether carvedilol can reduce renal damage induced by solar thermal effect in a 17 -day-long experiment. A solar emittor was used to develop solar erythema within the range 30% of the total body surface of narcotised experimental rats. The animals were randomly assigned to two equal groups (n = 7). Group 1 was treated with CVD at a dose of 10mg/kg/day administered in 1ml of saline i.p. Group 2 (placebo group) was given 1 ml of saline i.p./day. Protein and malonyldialdehyde (MDA) concentrations were determined in serum samples obtained on days 1, 8, and 17. Proteinuria and total protein loss per day were measured in urine samples daily. Serum protein levels of the two experimental groups did not differ significantly during the period under study. Serum MDA of the placebo group surpassed significantly that of the treated group on days 8 and 17 (p < 0.05). Protein concentrations in urine of CVD-treated animals were lower than those of the placebo group during the entire experimental period except for days 4 and 5 (p < 0.05 and p < 0.01). Total protein loss/day in urine shows similar differences between both groups (p < 0.05, p < 0.01). The results of our study show that in experimentally induced thermal injury carvedilol apparently protects renal function, by increased renal blood flow and by its antioxidant effect. Carvedilol, burns, renal function, free oxygen radicals It is known that high temperature does not cause only a local skin damage but impairs also the integrity of the organism with resulting functional affections of many organs and systems -systemic inflammatory response syndrome (SIRS) (Zogovic et al. 1996) . Lungs, heart, kidneys, liver and the coagulation system are the most commonly affected organs in burns. There are many factors during thermal injury that may harm renal functions. The most important are the decreased cardiac output, the respiratory failure with hypoxia and acidosis, toxaemia and sepsis. Hypovolemia with hypoperfusion, infection and endotoxaemia also play an important role in renal failure as part of the multiple organ failure syndrome (MOFS). Carvedilol is a multiple-action antihypertensive drug with selective α-adrenergic and nonselective ß-adrenergic blocking activity for treatment of mild to moderate hypertension. On the other hand, carvedilol inhibits the lipid peroxidation in myocardium, kidneys and the brain initiated by oxygen free radicals (Yue et al. 1992) .