Smoking down-regulates insulin receptor expression in rat skeletal muscle cells

The expression of insulin receptor gene in rat muscle was measured by RT-PCR,while insulin receptor protein content was detected by immunohistochemistry in the same tissue.The insulin receptor gene expression in the smoking subgroups(smoking only,high-fat diet,and diabetes models)was lower than that in the matched control ones(0.50±0.06 vs 0.84±0.09,0.38±0.01 vs 0.59±0.05,0.37±0.05 vs 0.55±0.05,all P<0.01).The same result happened in the protein content(6.99±0.53 vs 8.89±0.36,5.17±0.29 vs 7.53±0.53,2.16±0.56 vs 5.03±0.79,all P<0.01).Smoking appears to play a role in the molecular mechanisms leading to insulin resistance. Key words: Smoking; Insulin resistance; Insulin receptor; Muscle,skeletal