| Objective:Acute hypoxia is a pathological process in which abnormal changes in tissue metabolism,function,and morphology occur when oxygen supply is reduced or oxygen barriers are used for a short period of time,causing serious damage to important organs such as the heart,lungs,and brain.Hypoxia tolerance can reduce acute pathological injury of hypoxia and reduce complications and improve prognosis.Beta adrenergic receptors are distributed in various organs and tissues throughout the body.Sympathetic nerves are stimulated under stress.The release of epinephrine and norepinephrine binds to beta-adrenergic receptors on the myocardium to produce a positive myocardial effect and bronchial smooth muscle.The combination of beta-adrenergic receptors produces expanded bronchial effects to accommodate acute stress.At present,people mainly study the role of human sympathetic activity in the active adaptation process of chronic hypoxia,and there are few studies on the role of acute hypoxia.The purpose of this experiment is to study the expression of different?-AR genes in the myocardium of acute hypoxic rats and its correlation with hypoxia tolerance.Methods:A total of 24 SPF male Sprague Dawley rats were fed one week later.Three of them were used as control group(no hypoxia).The remaining 21 rats were given acute hypoxia.The rats were placed in hypoxia in turn.In the box,the flow rate of nitrogen was controlled so that the oxygen concentration in the anoxic tank began to decrease from 20.95%at a rate of 0.7%per minute until the rats died of hypoxia,and the survival time was recorded to reflect the hypoxic tolerance.According to the different survival time,divided into 3 intervals,0-15 minutes,15-20 minutes,20 minutes or more,each interval randomly selected 3 into the group,respectively,group A(low hypoxia tolerance/survival time 0-15 minutes),Group B(hypoxia tolerance/survival time 15-20 minutes),Group C(hypoxia tolerance/survival time 20 minutes or more).The rat was dissected and the heart was frozen for use.The expression of?1-AR mRNA,P2-AR mRNA and ?3-AR mRNA in rat myocardial tissue were detected by q-PCR.The expression of ?1-AR,?2-AR and P3-AR in rat myocardial tissue was detected by Western Blot.Protein expression levels;analysis of the relationship between hypoxia survival time and ?-AR mRNA expression levels and protein expression levels.Results:1.Compared with the control group,the expression of ?1-AR mRNA,?2-AR mRNA and P3-AR mRNA in group A(low hypoxia-tolerance group)was significantly decreased(P<0.01),and group C(high The expression of ?1-AR mRNA,?2-AR mRNA and ?3-AR mRNA in the hypoxic tolerance group increased significantly(P<0.01),while ?i-AR mRNA and ?2 in group B(hypoxia-tolerance group).There was no significant difference in the expression of AR mRNA and?3-AR mRNA(P>0.05).Compared with group A(hypoxia tolerance group),?i-AR mRNA,?2-AR mRNA,?3-AR mRNA expression in group B(hypoxia tolerance group)and group C(hypoxia tolerance group)The amount increased significantly(P<0.01).Compared with group B(hypoxia tolerance group),the expression of?1-AR mRNA,?2-AR mRNA and ?3-AR mRNA in group C(hypoxia tolerance group)increased significantly(P<0.01).2.Compared with the control group,the relative expression levels of ?1-AR,?2-AR and ?3-AR protein in group A(low hypoxia tolerance group)were significantly lower(P<0.01),and group C(high hypoxia tolerance The relative expression levels of(31-AR,P2-AR,and ?3-AR proteins were significantly increased(P<0.01),while ?1-AR,P2-AR,and P3-AR were observed in group B(hypoxia tolerance group).There was no significant difference in relative protein expression levels(P>0.05).Compared with group A(hypoxia tolerance group),the relative expression levels of ?1-AR,?2-AR and ?3-AR protein in group B(hypoxia tolerance group)and group C(hypoxia tolerance group)All increased significantly(P<0.01).Compared with group B(hypoxia tolerance group),the relative expression levels of ?1-AR,?2-AR,and ?3-AR protein in group C(hypoxia tolerance group)increased significantly(P<0.01).3.There was a significant positive correlation between hypoxic survival time and myocardial ?1-AR,?2-AR,?3-AR mRNA expression and protein expression levels,P<0.01 was statistically significant.Conclusion:1.Rat hypoxia tolerance increased with the increase of ?1-AR,?2-AR,P3-AR mRNA expression and protein expression levels.2.There was a significant positive correlation between the expression levels of ?1-AR,?2-AR,?3-AR mRNA and protein expression and the tolerance to hypoxia tolerance in rats.Objective:Acute hypoxia can cause serious damage to the heart,lungs,and brain of the body.Increasing hypoxia tolerance can reduce acute hypoxic injury and reduce complications and improve prognosis.Bone marrow mesenchymal stem cells have unique homing and repairing capabilities.They can be differentiated after transplantation into damaged heart tissue,replacing damaged cardiomyocytes,participating in the contraction of the host heart,secreting cytokines,and promoting angiogenesis in the ischemic region.Improve heart function.Therefore,the study of bone marrow mesenchymal stem cell transplantation to improve hypoxia tolerance.Methods:Twelve male Sprague-Dawley rats were randomly divided into four groups after one week of adaptive feeding.Each group consisted of three rats,group A(blank control group),group B(saline group),group C.(BMSCs treatment group),the remaining 3 rats were BMSCs-derived group(for 4 days after BMSCs transplantation,observe the survival of BMSCs in their myocardium),and group A,group B,and group C rats were placed into the hypoxia box in turn In the control,the flow rate of nitrogen infusion was controlled until the rats died of hypoxia,and the survival time was recorded to reflect the hypoxic tolerance.The BMSCs-derived group did not undergo hypoxia treatment and were normally reared.The expression of ?1-AR mRNA,? 2-AR mRNA and ? 3-AR mRNA in rat myocardial tissue were detected by q-PCR,and the ? 1-AR,?2-AR,and ?3-AR proteins were detected by Western Blot.The level of expression was compared.The difference in the time of hypoxia survival between BMSCs and other groups was compared.The correlation between BMSCs transplantation and ?-AR mRNA expression and protein expression was analyzed.Results:1.Compared with the control group A,the hypoxic survival time of group B(BMSCs treatment group)was significantly prolonged(P<0.01),while there was no significant difference in the hypoxic survival time of group B(saline group)(P<0.01).>0.05);Compared with group B'(saline group),survival time of group C(BMSCs treatment group)also significantly prolonged(P<0.01).Compared with control group A,there was no significant difference in resting heart rate between group B(saline group)and group C(BMSCs treatment group)(P>0.05);compared with group B(saline group),group C(treatment of BMSCs)There was no significant difference in the resting heart rate of the group.2.Compared with control group A,the expression of ? 1-AR mRNA,? 2-AR mRNA and ? 3-AR mRNA in group B(BMSCs treatment group)increased significantly(P<0.01),while group B(saline group)There was no significant difference in the expression of ? 1-AR mRNA,? 2-AR mRNA and ? 3-AR mRNA(P>0.05).Compared with group B(saline group),the expression of ? 1-AR mRNA,? 2-AR mRNA and ? 3-AR mRNA in group B(BMSCs treatment group)increased significantly(P<0.01).Compared with the control group A,the relative expression levels of ?1-AR,? 2-AR and ? 3-AR protein in group B(BMSCs treatment group)were significantly higher(P<0.01),while in group B(normal saline group)There was no significant difference in the relative expression levels of ?1-AR,? 2-AR and 0 3-AR(P>0.05).Compared with group B(saline group),the relative expression levels of ? 1-AR,? 2-AR and 0 3-AR protein in group B(BMSC treatment group)increased significantly(P<0.01).Conclusion:1.BMSCs transplantation can prolong the time of hypoxia tolerance and increase the ability of rats to resist hypoxia.2.The expression of ?1-AR,? 2-AR,? 3-AR mRNA and protein were significantly increased after BMSCs transplantation. |
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