The effect of triiodothyronine on changes of membrane fluidity in regenerating rat liver

The increase of the membrane fluidity during the early phase of liver regen eration after partial hepatectomy was described in literature in plasma mem brane and in microsomes. We found similar changes also in isolated mitochon dria and in crude total membrane fraction of the liver homogenate. The admi nistration of triiodothyronine to rats before partial hepatectomy diminishe d the increase of the membrane fluidity in the regenerating liver by 50 %. Triiodothyronine effect is explained by hormonal modification of lipid meta bolism in the regenerating liver.