| Objective:This study was designed to explore the change of islet beta cell function and the effect of adiponectin to rats with chronic intermittent hypoxia.Method:Forty-two adult male Sprague-Dawley (SD) rats were averagely divided into three groups by random number method. The control group was fed at atmospheric pressure and air environment cabins. The chronic intermittent hypoxia (CIH) group and the CIH with adiponectin (CIH+AD) group were fed in the cabins with low oxygen conditions (60 s/N2,60s/air, filling alternately, guarantee the oxygen concentration in cabins fluctuating between 5% and 21%). The CIH+AD group was additionally injected with adiponectin 10ug/100 g weight into caudal vein twice each week in Tuesday and Friday morning. The intermittent hypoxia time was 8:30 16:30 each day for a total of 5 weeks. Enzyme league immune assay (ELISA) was used to detect serum adiponectin, glucose, insulin, serum and pancreatic tissue oxidative stress indicators MDA level. Insulin positive area and apoptosis cells were double stained used terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) and immunofluorescence methods to detect the beta cell apoptosis and calculate the apoptosis rate. QRT-PCR method was used to detect pancreatic tissue apoptosis-ralated protein BAX and BCL-2, oxidative stress index superoxide dismutase (SOD), inflammation factors of tumor necrosis factor a (TNF a) and nuclear factors-kB (NF-kB) relatively expression of mRNA. The steady model evaluated (HOMA) method was used to assessment of insulin resistance (HOMA-IR) and p cell functions (HOMA-p)Results:The serum adiponectin level showed no significant difference (p>0.05) at the 3 groups before the study, but with a significantly decrease (p<0.01) in the CIH group at the end of the study. HOMA-IR index increased significantly (p<0.01) while HOMA-P value decreased adversely (p<0.05) in the CIH group. The mRNA relatively expression of MDA in serum and pancreatic, the apoptosis related indexes of BAX and BCL-2 in pancreatic, the inflammation index of TNF a and NF-kB in pancreatic significantly increased (p<0.01) in the CIH group. The inflammation related TNF a expression also increased in the CIH+AD group compared with the control group. Pancreatic P cell apoptosis rate rised when the expression of antioxidant SOD decreased significantly in the CIH group.Conclusion:The rat exposed to CIH condition manifested insulin resistance, β cell function reducing and apoptosis rising may due to the activated of mitochondrial oxidative stress and inflammation pathways. Adiponectin showed a significant anti-inflammatory and antioxidant effect, which could reduce and even reverse the occurrence of insulin resistance, islet β cell function and apoptosis when exposed to CIH condition. |
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