The Expression Of INOS And Changes Of Serum SOD Acativity, NO And MDA Content Of Rats With Pressure Ulcer

PurposePressure ulcer is one of the familiar complications of clinic,it is also the hard nut to crack of the clinical nursing,once occurrence,not only increase the sufferer's pain aggravate the original disease,prolong the course of illness,but also endanger the life of patients who is infected.There is a complicated and many factors participate pathologic process,among them,pressure is the most important and dangerous factor, the tissue that subjected to press is unsmooth bleeding of capillary vessel,the blood reflux get difficulty,then causing tissue lack of oxygen and nourishments,the restoration of blood flow to ischemic tissues causes addition damage,which is termed ischemia reperfusion injury(IRI).Up to the present,the IRI mechanism of pressure ulcer is still not quite explicit,so clarify the mechanism,explore the measures of prevention and treatment,easing or avoiding the harm,is the key of the prevention and cure pressure ulcer.Nitric oxide synthase(NOS) is endothelium-derived biosynthetic synthase.There are three isoforms of NOS:neuronal-NOS(nNOS),inducible-NOS(iNOS),endothelial -NOS(eNOS).nNOS and eNOS are called constitutive nitricoxide synthase(cNOS),its expression dependents on Ca²⁺ and CaM,rat skeletal muscle contains nNOS and eNOS, which catalyze nitric oxide(NO) production,and act as neurotransmitter and second messengers;iNOS is produced at injury,ischemia,inflammatory mediators,endotoxin, which expression is not dependent on Ca⁺ and CaM,Increased NO induced by iNOS may cause cytotoxic effect,immune response and injury of cell and tissue.During reperfusion of ischemic tissue,oxidative stress plays an important role in the IRI.NO play an important role during IRI,superoxide dismutase(SOD)is believed to play an important role in reversing the pathological damage caused by IRI, malondialdehyde(MDA) is one of the most sensitive indicator of lipid peroxidation,it is the end product of lipid peroxidation. IRI participates the development of pressure ulcer.However,it is yet unclear to the mechanism of its generation and the role which plays in pressure ulcer.The present study was made pressure ulcer on rat legs.We studied expression of iNOS in skeletal muscle and SOD acativity,NO,MDA content of serum.To explore the role of free radicals participate in the development of pressure ulcer.Materials and Methods54 Wister rats,weighing 180-220g(Animal laboratory of China medical university). The rats were divided randomly into 1 control group and 8 experiment groups,every group had six rats.The rats were made into narcosis with 10%Chloral Hydrate,lying on its back, using a 0.56 kg steel pillar perpendicularity press on the left legs,the muscle that mainly be subjected to press is vastus muscle and pectineus muscle,the steel pillar and the contact area of the bodies are the circular surfaces of the diameter 1 cm,unit area pressure was 70 kPas and kept 5 h.The vastus muscle was taken and with 4% paraformaldehyde and immersed in 30%sucrose-KPBS overnight at 4℃,embedded in OCT before placing frozen-embedded sections 8-10μm.Serum SOD activity,NO and MDA content were measured.1.skeletal muscle of experimental rats for HE staining to clarify physical pressure at different time points after the pathological structural changes in skeletal muscle.2.Extraction of serum in each group,the determination of nitrate reductase content of NO,SOD determination of xanthine oxidase enzymatic vitality and determination of thiobarbituric MDA content.3.Irnmunohistochemical staining method was used to observe physical pressure at different time points after iNOS in rat skeletal muscle fiber distribution and expression.4.Western-blot was used to detect the expression of iNOS in skeletal muscle.Result1.Control group of normal skeletal muscle fiber morphology,structure,clear,and orderly filaments with experimental rats carried out the structure of skeletal muscle injury,muscle fibers appeared vacuolation,dissolved,broken,edema,disappearance of cross striations,congestive vasodilator,interstitial edema,such as pathological changes. To IR24h the most weight,then gradually ease to IR4w tissue injury has not yet fully restored. 2.Most of the experimental groups in serum NO,SOD and MDA content of vitality compared with the control group were significantly different.Serum in rats with the SOD vitality of reperfusion time after a first increase in the trend of lower,NO, MDA levels increased after the performance of lower priority.3.In IR4h group,IR 12h group,IR 24h group,IR 3 days group,we can see that a large number of iNOS positive expression of skeletal muscle fibers,and the control group compared to the level of iNOS protein expression was significantly higher(P＜0.05).4.Detect the level of iNOS protein expression in control group,IR4h group,IR 12h group,IR 24h group,IR 3 days group with Western-blot,it increases significantly (P＜0.05);further inter-group comparison:IR12h group and IROh group,IR 4h group, IR1-week group,IR2-week group compared with high levels of iNOS protein expression,the difference is significant(P＜0.05);IR24h group and IROh group,IR 4h group,IR 3 days group,IRl-week group,IR2-week group compare with high levels of iNOS protein expression,the difference is significant(P＜0.05);IR4 and IR3-day week group,IR4h Group,IR12h Group,IR24h group compare to the low level of iNOS protein expression,the difference is significant(P＜0.05).Conclusion1.Ischemia-reperfusion injury participates in the formation of pressure sores,SOD activity and MDA content fluctuated Change.2.The damage of skeletal muscle is positive correlation with the content of NO and MDA and the expression of iNOS.iNOS activation pressure sores are ischemia-reperfusion injury in the course of free radical oxidative damage important aspect.