Biochemical and morphological alterations induced by long-term administration of epinephrine, metanephrine and thyroxine in rats

Abstract

Epinephrine, 1 mg/kg, metanephrine, 20 mg/kg, and thyroxine, 0.5 mg/kg, were injected sc for 6 weeks to rats. Epinephrine administration reduced body weight gain, increased the weight of heart, liver, kidneys and adrenal glands, increased the serum concentration of cholesterol and β-lipoproteins and decreased serum free fatty acid. Animals treated with epinephrine were less active but were more aggressive than control animals. Histopathologic alterations included loss of corrugation of elastic membranes of the aortic media and thickening of the intima in the aorta. Metanephrine in rats increased body weight when compared to controls and increased serum cholesterol concentration and β-lipoproteins. Neutral lipid accumulation and cholesterol deposits occurred in the aorta. Combined injections of epinephrine and thyroxine increased and mortality of rats but did not increase the severity of the histopathologic changes.