Expression of adenosine triphosphate-sensitive potassium channels in rats with cirrhosis: correlationship with sympathetic activity and renal function

Abstract

Objective: The aim of this study was to perform a direct analysis ofKATP mRNA expression by RT-PCR in kidney and isolated aorta fromrats with cirrhosis (induced by carbon tetrachloride) and controls.The present study also analyses the relation between induced cirrhosisand urinary excretion of sodium and sympathetic activity in cirrhoticrats. Methods: Rats were placed in metabolic cages and allowedfree access to food and water. Cirrhosis was induced by repeateddoses of carbon tetrachloride by gastric gavage. After some weeks,the kidney and aorta were dissected and utilized for RNA extraction.Blood and urine were analyzed for electrolytes. Renal function wasestimated by creatinine clearance and sodium urinary excretion.Serum catecholamines were measured by HPLC analysis. Results:First, RT-PCR analysis showed that KATP mRNA is expressed in liverwith cirrhosis and intense fibrosis, but not with moderate fibrosis.Second, RT-PCR analysis revealed that KATP mRNA was detectedonly in aorta dissected from rats with cirrhosis. Finally, an enhancedreabsorption of sodium without renal failure suggests a potentialmediator would increase the activity of the sympathetic system.Conclusion: These results suggest that KATP mRNA is expressed incirrhotic rats with sympathetic activation and renal dysfunction. Thischannel might be involved in another route where the vascular tonecan be modulated in cirrhosis.

Keywords

• Potassium channels/analysis
• Adenosine triphosphate
• Sympathetic nervous system/pathophysiology
• Liver cirrhosis
• experimental
• Kidney/physiology
• Sodium/urine
• Carbon tetrachloride
• Rats