The Effect Of Hypertonic Solution Chloride Hydroxyethyl Starch On Myocardial Cells Of Rat In Hemorrhagic Shock

Objective By producing the rat models with hemorrhage shock, to explore the effects of HSH on the changes of ATPase activities in cardiac cell membrane, Ca²⁺ and mitochondrial membrane potential of cardiac myocytes in hemorrhage shock rats, and offer a relevant evident on resuscitation treatment of hemorrhagic shock.Method The study includes two parts. Part one: Ninety-six Wistar rats wererandomized into two groups : hyperosmotic solution (HSH, n=48) and 0.9%sodium chloride injection (NS, n=48) .Hemorrhagic shock model was performedby a gradient volume-control phase combined with an adjustment phase throughbloodletting from femoral artery and keeping mean arterial pressure at(4.0±0.7)Kpa.At the different timepoint (pre-shock stage, shock,post-resuscitation 30min, 60min, 90min,120min), eight rats were experimentized.The ATPase activities of cardiac cell membrane and the myocardial pathologicchanges were investigated in different periods. Part two: Eighty-four Wistar ratswere randomized into two groups : hyperosmotic solution (HSH, n=42) and 0.9%sodium chloride injection (NS, n=42). At the different timepoint (pre-shock stage,shock, post-resuscitation 5min, 15min, 30min, 60min, 90min), cultured cardiacmyocytes , some were stained with JC-1, used fluo-4/AM as calcium probe, theothers were assayed for Ca²⁺ mitochondrial membrane potential by flow cytomety.Results Part one: (1) The three ATPase activities of cardiac cell membraneat shock declined in two groups (P<0.01) .It is obvious for Na⁺-K⁺-ATPase andGa²⁺-ATPase. (2) Compared with pre-shock stage, the ATPase activities of groupHSH at post-resuscitation 90min ,120min reduced (P<0.05) . The activities atpost-resuscitation were higher than shock (P<0.01) .(3) There was statisticallysignificant difference between post-resuscitation and pre-shock stage in group NS (P<0.01) .The ATPase activities at post-resuscitation 90min ,120min were lower than shock (P<0.01 ) .(4) The ATPase activities of group HSH at post-resuscitation were higher than those of group NS (P<0.01) .(5) The myocardial pathologic changes of group HSH at post-resuscitation 60min were better than those of shock and post-resuscitation 60min of group NS. Part two:(1) Ca2+ of group HSH at shock, post-resuscitation 5min, 15min, 30min was higher than that of pre-shock stage, but mitochondrial membrane potential at post-resuscitation 60min, 90min was lower (PO.01) . (2) At shock and post-resuscitation Ca2+of group NS was higher than that of pre-shock stage, and mitochondrial membrane potential was lower (P<0.01) ,but there were not significant deviation after resuscitation as compared with that at shock (P>0.05).( 3 ) Ca+ and mitochondrial membrane potential of group HSH at post-resuscitation 60min, 90min were more significantly different than that of group NS (P<0.01) .Conclusion 1. Hypovolemic shock can alleviate the ATPase activities of cardiac cell membrane ,increase the use of energy and lead to inhibition of ionic pump functions. 2. The ischemia-reperfusion can aggravate Ca2+ overload in cardiac cell and result in the myocardial structure injure during resuscitation. 3. HSH can restore the activities of ionic pump functions, improve Ca2+and stabilize mitochondrial membrane potential.