RESUMO
OBJECTIVE: To investigate the effect of smoking and smoking cessation on the phosphorylation of IKK-ß in type 2 diabetic rats. METHODS: Forty-two six-week-old Wistar rats were randomly divided into 4 groups: normal control (NC, n = 7), diabetes control (DC, n = 7), diabetes with smoking (DS, n = 14) and diabetes with smoking cessation (SC, n = 14). Rats in DS and SC groups were further assigned randomly into 8w and 12w subgroups. DS group was given passive smoking twice a day for 8 or 12 weeks, while SC group ceased passive smoking for 4 weeks after 8 or 12 weeks of smoking. Western blot method was used to detect the level of IKK-ß phosphorylation in skeletal muscle. RESULTS: Compared with the NC group, the phosphorylation of IKK-ß protein in DC group was increased (0.16 ± 0.05 vs 0.30 ± 0.08, P < 0.01). There was an increasing trend with the phosphorylation level of IKK-ß in the DS (8w) subgroup, but there was no statistical difference between the DC group and SC (8w) subgroup (0.40 ± 0.09 vs 0.30 ± 0.08, 0.36 ± 0.10, P > 0.05). The phosphorylation level of IKK-ß in DS (12w) group increased obviously, being significantly higher than that in the DC group and SC (12w) subgroup (0.74 ± 0.11 vs 0.30 ± 0.08, 0.35 ± 0.07, P < 0.01). CONCLUSION: With the prolongation of smoking duration, the phosphorylation of IKK-ß in type 2 diabetic rats increased. After smoking cessation, the phosphorylation of IKK-ß decreased. The phosphorylation of IKK-ß may be involved in the mechanism by which smoking causes type 2 diabetes.
