Study of the effect of thyroid gland dysfunction on the blood levels of caspase-3, some mediators of innate inflammation, matrix metalloproteinase-9 and some liver functions in rats

ABSTRACT

In the present study we have measured the concentrations of serum IL-6, TNF-alpha, MMP-9 and hepatic caspase-3 activity in rats with hypothyroidism and hyperthyroidism together with total T[3], AST and ALT. We have evaluated the effect of thyroid dysfunction in an experimental model. We studied 45 rats. Fifteen served as controls, 15 rats were hypothyroid and 15 were hyperthyroid. Serum ALT and AST were found to be significantly higher in the hyperthyroid group. Serum IL-6 and TNF-alpha concentrations were significantly higher in the hyperthyroid group compared to the hypothyroid group. The mean values of hepatic caspase-3 were significantly elevated in the hyperthyroid group as compared to the control group. Less caspase-3 activity was found in the hypothyroid group compared to the control group. The mean values of MMP-9 were found to be significantly increased in the hyperthyroid group as compared to both the hypothyroid and the control groups. Our study shows that excess T3 causes liven dysfunction through the following mechanism [s] 1] inducing apoptosis, as a result of activation of a mitochondnia-dependent pathway; 2] direct toxic effect, as evidenced by increased levels of proinflammatory cytokines IL-6 and TNF-alpha; 3] elevated MMP-9 levels may also reflect a possible role for Kupffen cells in the hepatocellular response to hepatic injury by secretion of MMP-9