Association Of Vascular Injury Factors With Vascular Injury Induced By Local Vibration

Objectives In this study,a combination of occupational epidemiology and animal model was used to investigate myosin light chain 2?MLC2?,endothelin-1?ET-1?,5-hydroxytryptamine?5-HT?and vinculin?VCL?.The correlation between vascular injury factors and vascular injury induced by local vibration analysis of its significance and role in the diagnosis of vibration-induced white finger?VWF?,thus providing a scientific basis for the clear pathogenesis and early diagnosis of HAVD.Methods?1?Occupational epidemiology study:Through questionnaires,using the method of judgment sampling,61 hand-transmitted vibratory workers with VWF symptoms were VWF group by reading the self-reported and doctors examined VWF;61 hand-transmitted vibratory workers were consisted by the vibration contact group;64 non-vibration workers were the control group.After plasma was collected from workers,enzyme-linked immunosorbent assay?ELISA?was used to detect the expression levels of MLC2,ET-1,5-HT and VCL in plasma.Through statistical correlation analysis,the index with the highest diagnostic value of VWF was selected.?2?Animal experiment:Thirty-two male SD rats were selected as experimental subjects,aged 7-8 weeks old,with an average body weight of 211.3±11.1 g,randomly divided into three groups:?1?control group:14 rats/group without vibration;?2?7 days vibration group:9 rats/group,continuously vibration for 7 days;?3?14d vibration group:9 rats/group,continuous vibration for 14 days.Vibration conditions:vibrated every day for 4 hours,the frequency weighted acceleration was 49m/s²,and the vibration direction was one-way vertical vibration.The control group had the same conditions except no contacting vibration.After vibration was completed,the rats were anesthetized,blood was collected from the abdominal aorta,and the rat's ventral mid-mural artery was dissected to make tail pathological sections and ultrathin sections for observation under optical and transmission electron microscopes,including pathological morphology and subcellular structures.The ELISA assay was used to detect the expression levels of MLC2,ET-1,5-HT,and VCL in the plasma of those three groups.The statistical analysis of the experimental results was performed using SPSS23.0.Results?1?The expression level of MLC2 in the plasma of the three groups of workers was found to be statistically significant after comparison between multiple comparisons??²=74.920,P<0.05?.There were statistically differences between the three groups in comparison each other.The level of MLC2 expression in workers'plasma was in the order of VWF>vibration contact group>control group;the expression levels of ET-1 in plasma of the three groups of workers were statistically significant??²=12.62,P<0.05?,there was a statistically difference between the VWF group and the control group?P<0.05?.After 5-HT and VCL were compared among multiple groups of M,no significant difference was found(?₁²=3.29,?₂²=4.24,P_1,2>0.05).Univariate and multivariate logistic regression analysis revealed that elevated MLC2level was the risk factor for VWF?OR=1.001,P<0.05?.The higher ET-1level was the protective factor of VWF?OR=0.975,P<0.05?excluded after eliminating the effects of age,length of service,smoking,and alcohol consumption.The ROC curve was further plotted.The A_Z of MLC2,ET-1,and the predictive probability were 0.793>0.539>0.765 in descending order.There was no significant difference between MLC2and sputum A_Z?P>0.05?.Both A_Z were higher than ET-1?P<0.05?.?2?The rat tail artery blood vessels were examined by pathological examination.The results showed that the rat tail artery blood vessels in the control group were normal under optical microscope,and the elastic intimal membrane?IEM?was continuous wavy and smooth.The smooth muscle cells?VSMC?were arranged neatly;under the electron microscope,the VSMC were arranged closely,no vacuoles were observed,and the blood vessels slightly shrank.In the 7d vibration group,the discontinuous phenomenon of IEM was observed under the optical microscope.Under the electron microscope,the vacuolation of VSMC layer and the swelling of vascular endothelial cells?VEC?were observed.In 14d vibration group,part of IEM was observed to be discontinuous or even disappeared under electron microscope.VSMC and IEM layer appeared vacuolization and VEC rupture appeared under electron microscope.Vascular injury was more serious than 7d vibration group.There showed that the longer the vibration exposure time,the more serious the damage of the vascular endothelium.The ELISA assay found that the mean expression level of MLC2 in the three groups was not completely the same in rat plasma,and the lowest in the control group,and the highest in the 7d vibration group??²=3.80,P<0.05?.The overall average expression levels of ET-1 and 5-HT in the three groups were not all the same,and the overall average expression level was highest in the control group,lowest in the 14-day vibration group,and the difference in expression levels between the three groups was statistically significant.Significance??₁²=4.30,?₂²=17.78,P<0.05?.Conclusions?1?In this study,occupational epidemiology survey and experimental results showed that the levels of plasma MLC2 and ET-1 in VWF workers were related to VWF,and MLC2 was better than ET-1 as a biomarker to screen VWF.The relationship between the expression level of 5-HT and VCL and the presence or absence of VWF remained to be further studied.?2?Through the morphological observation of rat-tail vibration model,it was found that the degree of vascular injury was aggravated with the increase of vibration exposure time.The expression of MLC2,ET-1 and 5-HT in rat plasma was associated with vascular injury caused by local vibration.No correlation was found between the expression level of VCL and the presence or absence of local vibration.