RESUMO
OBJECTIVE: To study the regulation of chromium on gene expression related to metabolism of skeletal muscles in diabetic rats. METHODS: Male Wistar rats were assigned to three groups: normal control group (NC), alloxan-induced diabetic control group (DM), and DM with chromium supplementation group (DM + Cr). 200 microg Cr/kg bw perday was supplemented orally for 60 days. At the end of the treatment, the changes in gene expression among three groups were studied by mRNA differential display technique combined with cDNA fragments cloning, sequencing and BLASTn analysis. RESULTS: 11 cDNA fragments larger than 400bp expressed differences in skeletal muscles between DM + Cr group and DM group were isolated, 4 of them expressed higher in DM + Cr group, while the rest expressed higher in DM group. Cr-3 and GLUT4 are homologous with sequence identities of 98% and Cr-5 and IRS-1 are homologous with sequence identities of 100%. The expression level of GLUT4 mRNA in DM + Cr group are higher than those of DM group. CONCLUSION: Chromium supplementation could induce the expression of GLUT4 mRNA on skeletal muscles in diabetic rats. It may be one of the molecular mechanisms that chromium could improve the disorders of glucose and lipids metabolism in diabetic rats.
Assuntos
Cromo/farmacologia , Diabetes Mellitus Experimental/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Transportador de Glucose Tipo 4/metabolismo , Músculo Esquelético/metabolismo , Animais , Cromo/administração & dosagem , DNA Complementar/genética , Transportador de Glucose Tipo 4/genética , Masculino , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: To study the effects of chromium supplementation on related gene expression to metabolism of skeletal muscles in diabetic rats. METHODS: cDNA fragments from the out related research were cloned, sequenced and its comparalarity analysis has been done. The RT-PCR were made using the primers designed according to the sequence of cDNA. RESULTS: The identities between the sequence of Cr-5 and IRS-1 is 100%. The expression level of DM group (0.791 +/- 0.038) is obviously lower than those of normal group (0.892 +/- 0.053, P < 0.05). And The expression level of DM + Cr group (0.822 +/- 0.066) have some improvement compare to those of DM group (P > 0.05). CONCLUSION: There is a tendency that Chromium supplementation can increase the expression level of IRS-1 mRNA of skeletal muscles in diabetic rats. It will be studied as a candidate gene in future research.
