Study Of The Effect Of Different Exercise Time On Urotensin Ⅱ And GPR14 In Insulin Resistance Rats

Objective:Urotensinâ…¡,originally isolated from the teleost urophysis, has been reported as the most potent known vasoconstrictor.It was recently identified as an endogenous ligand for G-protein-coupled receptor 14(GPR14).Diseases closely related with insulin resistance had great impact on the human health and made more people living unhappily. More attention had been paid on aerobic exercise for it improved the insulin resistance effectively.Much more had to be studied to elucidate the exact mechanism of it.To provide more theoreticalbasis for exercise advices of insulin resistance,Urotensinâ…¡and GPR14 in heart,aorta and skeletal muscle of both normal and insulin resistancerats were observed under different exercise time.Methods:To establish the rat model of insulin resistance,high fat feeding were given to 60 SD rats.Normal rats were divided into four groups randomly:normal control group(N0),normal rats swimming 1 hour a day (Nl),normal rats swimming 2 hours a day(N2)and normal rats with exhausted swimming(N3),10 rats in each group.High fat feeding rats were also divided into four groups randomly:high fat feeding rats without exercise(G0),high fat feeding rats swimming an hour a day(G1),high fat feeding rats swimming 2 hours a day(G2),high fat feeding with exhausted swimming(G3).15 rats were in each group.TG,TC,HDL,LDL and glucose in serum were examined by auto-biochemistry analysis machine. Urotensinlâ…¡and insulin in plasma were detected by radioimmunoassay. Immunohistochemistry technique was applied to observe the content of Urotensinâ…¡and GPR14 in heart,aorta and skeletal muscle.The expression of Urotensinâ…¡mRNA and GPR14 mRNA in these tissues were detected by Real-time PCR.Results:Compared with normal rats,TG,TC,LDL,fasting blood glucose and insulin were all increased,while Insulin sensitive index was declined in high fat feeding group.Urotensinâ…¡in plasma were declined after aerobic swimming exercise,but declined after exhausted swimming in both normal and insulin resistance group.The level of Urotensinâ…¡and GPR14 in heart,aorta and skeletal muscle of normal rats were declined after aerobic swimming exercise but no significance was observed.The level of Urotensinâ…¡,GPR14,Urotensinâ…¡mRNA,GPR14mRNA in heart,aorta and skeletal muscle of insulin resistance rats were declined after aerobic swimming exercise,significance was also observed.The level of Urotensinâ…¡and GPR14 in heart,aorta and skeletal muscle was increased after exhausted swimming.Conclusions:Successful insulin resistance rats model were established by feeding high fat feedings.Exercise may take part in the body regulating by changing the Urotensinâ…¡in plasma.In both normal and insulin resistance rats,changes of Urotensinâ…¡and GPR14 induced by aerobic exercise were mainly in translation level or protein aero-structure,not in transcription level.The changes of Urotensinâ…¡and GPR14 indicated that Urotensinâ…¡binding with GPR14 played a role by autocrine and paracrine in tissues.Urotensinâ…¡also took part in the regulation of exercise stress in normal and insulin resistance rats.