| PurposeHypoxic-ischemic encephalopathy(HIE) is a hypoxic brain lesion caused by perinatal asphyxia ,serious can lead to both permanent nerve injury and multiple organs injury ,a heart is one of the most easily impaired organs.. Recently an investigation data manifested that brain injury could induce heart disfunction and hemodynamics disorder,considered this was a change of functionality. But there are not much related investigations and effective medicines.Meglumine cyclic adenylate, as a medicine of cyclic adenosine monophosphate, have been extensively used to treat heart failure,coronary artery disease et al,but its effect to neonate need been studied and researched again.In this study,we established the animal model with HIE for dynamic diagnosis and therapy; from morphology investigated myocardium lesion in neonate with HIE, and its prevention and therapy by meglumine cyclic adenylate ,provided objective reference for early diagnosis and therapy of HIE.Methods1. animal group and methods22 term piglets at an age of 3 to 7 days after birth were subjected and divided into sham operation group,Hypoxic-ischemic encephalopathy(HIE)group and Meglumine cyclic adenylate(MCA)group; sham operation group:4 piglets were subjected to only segregate bilateral common carotid artery, HIE group:9 piglets were subjected to block bilateral common carotid artery temporarily and give 6% oxygen mechanically,MCA group : 9 piglets were subjected to inject MCA in vein before ischemia.2. measure cardiac troponinBefore hypoxia and 10 hours after hypoxia ,we drew blood 2ml from a vein ,centrifuged it,took serum ,measured cardial troponin I level.3. MR imagingMR imaging was performed 12h after hypoxia respectively with the thickness of 3~5mm.4. pathological examination of cardial tissueOn pathological slices ,we observed edema,hemorrhage(HE stain),on super thin slices,we observed the morphological changes of cellular ultrastructrure (transmission electron microscrope)Result1. cardial troponin I resultIn several groups the values of cardial troponin I before hypoxia are not significantly different(P>0.05) .10 hours after hypoxia the values of cardial troponin I in HIE group was higher than that in sham group ,there is significant difference between them( P < 0.01), 10 hours after hypoxia the values of cardial troponin I in HIE group was higher than that in MCA group ,there is significant difference between them ( P < 0.01), 10 hours after hypoxia the values of cardial troponin I in MCA group was higher than that in sham group ,there is significant difference between them( P < 0.05).2. MR imaging resultlow signals was shown in sham operation group;high signals was shown in HIE group and MCA group.3. HE resultIn sham operation group arrangement of myofilament was regular,the cells of myocardium did not swell, cell nuclei did not change. In HIE group blood vessels bled and were engorged acutely. Plentiful phlogistic cells infiltrated, severely, myofilament bleak, cell nuclei vanished, necrosis was clear .In MCA group a few blood vessels bled and were engorged, myofilament swelled lightly, a few phlogistic cells infiltrated.4. myocardium ultrastructur resultIn sham operation group myocardium ultrastructure was essentially integrated, arrangement of myofilament was regular, the shade was distinct , mitochondria were abundant and integrated , cristae were clear;In HIE group , arrangement of myofilament was not regular, many broke ,the bulk of mitochondria fragmentated and vanished , cristae vanished, In MCA group the change of myocardium ultrastructure was lighter than HIE group ,only minority mitochondria swelled lightly, myofilament dissolved lightly.conclusion1. Using piglet model with hypoxic-ischemic in the whole brain and control breath to simulate human HIE was a reliable method.2. In asphyxia piglets the changes of cardial structure was the pathological basic of heart disfunction and hemodynamics disorder; in addition ,myocardium injury resulted from brain lesion ,including hypoxia.3. MCA might prevent and treat myocardium injury in neonatal swines with hypoxic-ischemic encephalopathy.
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