Effect Of Conjugated Linoleic Acid And Hypoxia On Lipid Metabolism Of Skeletal Muscle In Rats

Methods:A total of96male Sprague-Dawley (SD) rats weighing100±20g. All animals were allowed to acclimatize for a week on normal diet before grouping, the rats were then randomly divided into three groups of32:the control group (CON), fed a regular diet; the CLA group (CLA), fed a added CLA diet; the CLA plus hypoxia group (CH), fed a added CLA diet, which is of similar feed formulation as group CLA, and exposed to hypoxia. After one week, three groups feed the corresponding diet for45days, and then the group CH put into hypobaric chamber to simulate altitude hypoxia of5km for another1month. At the same time, CON, CLA, CH three groups are divided into four groups of1day,10days,20days,30days respectively. The blood and muscle of rats were taked, and glucose, triglyceride, tissue lactic acid, muscle glycogen, free fatty acids, insulin, fatty acid synthase (FAS), lipoprotein lipase (LPL), hormone sensitive esterase (HSL) were measured.Results:The body weight and food intake of rats were obviously no influence by CLA(P>0.05) and decreased by hypoxia(P<0.01). In different hypoxia duration, serum glucose of different groups have no significant differences(P=0.87; P=0.81; P=0.05;P=0.14). In different hypoxia durations, serum triglyceride of CLA group in first day significant higher than CON group(P<0.01), serum triglyceride of CH group in first day significant higher than CON group(P<0.01), serum triglyceride of different groups have no significant differences in other durations. In different groups, serum triglyceride have no significant change with the extension of time. In different hypoxia durations, serum FFA of CLA group significant higher than CON group(P<0.01), serum FFA of CH group significant lower than CLA group(P<0.01). In different groups, serum FFA show upped first and then decreased trend with the extension of time. In different hypoxia durations, serum insulin of CLA group significant higher than CON group(P<0.01), serum insulin of CH group significant lower than CLA group(P<0.01). In different groups, serum insulin show upped first and then decreased trend with the extension of time. In different hypoxia durations, intramuscular glucose of CLA group in first day significant lower than CH group(P<0.05), intramuscular glucose of CON group and CLA group in tenth day significant higher than CH group(P<0.05), intramuscular glucose of different groups have no significant differences in twentieth days, intramuscular glucose of CON groups and CLA group significant higher than CH group(P<0.01). In CH groups, intramuscular glucose decreased in tenth day and thirtieth day. In different hypoxia durations, intramuscular lactate of CON group in first day significant lower than CLA group(P<0.05), intramuscular lactate of different groups have no significant differences in other durations. Intramuscular lactate of CLA group and CH group decreased with the extension of time, meanwhile CON group have no significant differences. In different hypoxia durations, intramuscular triglyceride of different groups have no significant differences(P>0.05). In CH group, intramuscular triglyceride decreased in tenth day and twentieth day, In CLA group, intramuscular triglyceride decreased in the twentieth day. In different hypoxia durations, intramuscular glycogen of different groups have no significant differences in first day, twentieth day and thirtieth day(P>0.05), intramuscular glycogen of CON group significant higher than CH group(P<0.01). In different groups, intramuscular glycogen show decreased first and then upped trend with the extension of time. In different hypoxia durations, intramuscular FFA of CON groups significant lower than CLA group(P<0.01), intramuscular FFA of CLA groups significant higher than CH group(P<0.01), intramuscular FFA of CON groups significant higher than CH group (P<0.01). In different groups, intramuscular FFA show upped first and then decreased trend with the extension of time.In different hypoxia durations, the content of HSL in CLA groups significant higher than CON group(P<0.01), the content of HSL in CH groups significant lower than CLA group(P<0.01). In CON group, the content of HSL increased in the twentieth day, in CH group, the content of HSL increased in the tenth day and twentieth day. In different hypoxia durations, the content of LPL in CLA groups significant lower than CON group(P<0.01), the content of LPL in CH groups significant higher than CLA group(P<0.01). In CON group, the content of LPL increased in the twentieth day, in CLA group, the content of HSL increased in the tenth day and twentieth day. In different hypoxia durations, the content of FAS in CLA groups significant lower than CON group(P<0.01), the content of FAS in CH groups significant lower than CLA group (P<0.01). In CLA group, the content of FAS increased in the twentieth day, in CH group, the content of HSL increased in the tenth day and twentieth day.