Activation Of PVAT By Long-term Exercise Contributes To Restoration Of Vascular Function In Obese Rats

Objective:Obesity will lead to cause vascular dysfunction,and endothelial nitric oxide（e NOS）in perivascular adipose tissue（PVAT）may be more important than endothelium in the regulation of vascular function.This research mainly discussesed activation of PVAT by long-term exercise contributed to restoration of vascular function in obese rats.Methods:6-month-old SD male rats were randomly divided into normal diet control group（NC）,normal diet exercise group（NE）,high fat diet control group（HC）and high fat diet exercise group（HE）.Rats were subjected to moderate intensity aerobic(55-65%VO_2max)treadmill training for 17 weeks（20 m/min,60 min/d,5 d/wk）.By measuring the weight of rats and Lee’s index for determining obesity model establishment,enzyme-linked immune detection rats blood physiological index and inflammatory factor index,HE staining to observe rat vascular morphology,NO immunofluorescence test the production of NO in the thoracic aorta of rats and PVAT,determination of in vitro microvascular vascular tension and drug sensitivity e NOS,protein immunoblot analysis.One-way and multiple comparisons analysis of variance and were used.Results:（1）Comparison of body weight and Lee’s index showed that the body weight of HC group was significantly higher than that of NC group（P<0.01）;the body weight of HC group was significantly higher than that of NC group（P<0.05）;the body weight of HE group was significantly lower than that of HC group（P<0.05）.（2）The basic physiological indexes of blood,glucose,Insulin,TG,TC and LDLin HE group were significantly higher than those in HC group（P<0.01）,and HDL content was significantly higher than that in HC group（P<0.01）.The levels of IL-6,CRP,Adiponectin,TNF-α,Leptin,Resistin,AngⅡand NO in the HE group were significantly higher than those in the HC group（P<0.01）.（3）Morphological results of HE staining of thoracic aorta and PVAT showed that the lipid droplet volume in HC group was significantly higher than that in NC group（P<0.01）.The lipid droplet volume in HE group was significantly lower than that in HC group（P<0.01）.（4）Compared with HC group,NO content in HE group was significantly increased（P<0.05）in the quantitative fluorescence test of NO in thoracic aorta and PVAT of rats.（5）In vitro microvascular measurement of vascular tension and drug sensitivity,ACH-induced vasodilation results showed that in HC group,there was a significant difference between the vascular ring with and without PVAT in vitro（P<0.05）.The results of SNP-induced endothelial-independent dilation were observed.In the HE group,there was a significant difference in the sequence of vascular rings with and without PVAT（P<0.01）.There was a significant difference in p IC₅₀（P<0.01）.（6）The experiment results of e NOS and its phosphorylated protein expression in thoracic aorta PVET,the e NOS content in thoracic aorta of NE rats was significantly higher than that of NC group（P<0.01）,and the e NOS content in thoracic aorta of HE group was significantly higher than that of HC group（P<0.01）.Conclusions:Long-term exercise intervention can effectively control the weight of obese rats and improve the function of fasting blood glucose metabolism and lipid metabolism in blood.The level of inflammatory factors in blood was decreased,the level of vasodilator factor was increased,the morphology of lipid droplets in PVAT of thoracic aorta was decreased,the content of NO and the activity of e NOS in PVAT of thoracic aorta were increased.Long-term exercise can also restore the anticonstrictive effect of PVAT on blood vessels,which may be endothelial-independent,and this regulatory effect may be related to the activity of e NOS in PVAT.