Nuclear calcium oscillation in cultured neonatal rat myocytes / 中国病理生理杂志

AIM: To determine whether nuclear Ca 2+ is independently regulated from the cytosolic Ca 2+ and nuclear Ca 2+ oscillation induced by many modulating factors in cultured rat neonatal myocytes and its mechanism. METHODS: Rat neonatal cardiac myocytes were cultured, and fluo-4/AM was loaded as calcium probe. The changes of cytosolic and nuclear Ca 2+ were observed by confocal laser microscopy. RESULTS: Calcium fluorescent intensity oscillated slightly in myocardiocytes and the average intensity was much higher in the nucleus than that in the cytosole. Ca 2+ oscillation in nucleus and cytosole induced by norepinephrine, isoproperenol, ATP were completely blocked by Ca 2+ -ATPase antagonist thapsigargin (10 -6 mol/L),L-type Ca 2+ channel blocker verapermil (500 ?mol/L) and KCl (20 mmol/L). Ca 2+ -ATPase antagonist thapsigargin completely blocked the propagation of Ca 2+ waves and simutaneouly induced a temporary Ca 2+ increase followed by a magnificient drop and loss of response to norepinephrine. CONCLUSIONS: The results suggested that generation and maintenance of calcium oscillation both in cytosole and nucleus depended on extracellular Ca 2+ influx, membrane potential, Ca 2+ release and uptake of cytosolic and nuclear calcium stores. The difference between cytosolic calcium and nuclear calcium indicated that calcium regulating system relatively independent of cytosole may exist in nucleus.

ULTRASTRUCTURAL OBSERVATION ON HUMAN LUNG TISSUE AND MYOCARDIUM DIED OF CRANIOCEREBRAL PENETRATING GUNSHOT WOUND / 中国法医学杂志

U1 trastuctrural changes of myocardium and lungs from 6 cases died of cranioce-rebral penerating gunshot wound 2 hours after injury is reportcd.In all cases theelectron microscopy of the myocardial and lung tissue samples showed the similar ultrastructural morphological changes of the cells and interstitial tissues.The mostpr-ominent ultrastructural changes of myocardium were disorderly arrangement of the Zband.focal dissociation of the myofibrills,mitochondrial swelling with decreasing ofmatrix density and disruption of cristae,and interstial edema.The changes of theung tissue were increasing of width of alveolar septa with decreasing of the electron density.Aggregation of neutrophils in the capillaries of alveolar septa and some alveolar space was observed.The significance and the pathogenesis of the mainpathological changes were discussed.It is suggested that the pulmonary interstitialedema was neurogenic.The pulmonary edema may be manifested as interstitial edemaor intra-lveolar edema depending upon the time elapsed after the gunshot injury.