Thyroxine as a stimulator of liver regeneration after partial hepatectomy: an experimental animal study.

Twenty six male albino rats were divided into a control group (6rats) (G) exposed to Sham operation and two experimental groups (G1 & G2) of 10 rats each. 2/3 partial hepatectomy (PH) was performed in G1 and T4 was administered orally in a dose of 4 mg/kg 10 days prior to PH in G2. Animals were sacrificed 24 hours following PH and Sham operation. Liver sections were immunohistochemically stained for anti-cyclin D1 & anti-VEGF antibodies. Positive reaction was in the nuclei of hepatocytes and in lining of hepatic blood sinusoids respectively. The morphometric determination of the count of cyclin D1 positive nuclei and area % VEGF positive lining of the blood sinusoids was performed in the different groups. Multiple cyclin D1 positive nuclei were detected in liver sections of rats receiving thyroxine prior to PH confirmed by significant increase in the mean count of immuno-positive nuclei as compared to G & G1. VEGF positive immuno-reaction was in the lining of multiple hepatic blood sinusoids on thyroxine therapy proved morphometrically by a significant increase in mean area % in G2 versus G1. The results showed a stimulating effect of thyroxine on liver regeneration following 2/3 partial hepatectomy evidenced by increased Cyclin D and sinusoidal endothelial VEGF expression.