[Adiponectin knockout mice].

Here we investigated the biological functions of adiponectin, a fat-derived hormone, by disrupting the gene encodes it in mice. Adiponectin knockout mice (KO) exhibited severe diet-induced insulin resistance with reduced IRS-1-associated P13-kinase activity in muscle. KO also revealed severe neo-intimal thickening in response to vascular-injury and hypertension induced by salt diet. Carbon-tetrachloride induced severe liver fibrosis in KO with the elevated gene expression of growth factors. These phenotypes in KO were reversed by viral-mediated production of adiponectin. Our results indicate that adiponectin should be one of key molecule of the metabolic syndrome and may be a new therapeutic target for the metabolic syndrome.