title: [The relationship between sarcoplasmic reticulum Ca(2+) modulation proteins and postresuscitation myocardial dysfunction].
abstract: OBJECTIVE
  To investigate the relationship between sarcoplasmic reticulum Ca²⁺ modulation proteins and postresuscitation myocardial dysfunction.
  
  
  METHODS
  Thirty-eight SPF male Sprague-Dawley (SD) rats were randomly divided into control group (n=12) and cardiac arrest (CA) group (n=26). CA was induced by intravenous bolus of potassium chloride (40 μg/g), and cardiopulmonary resuscitation (CPR) was conducted 8 minutes later. No CA was induced in control group except catheter placement for monitoring cardiopulmonary parameters after anesthesia. Invasive hemodynamic parameters were monitored for 1 hour after CPR. Echocardiogram was performed to evaluate cardiac function. Myocardial samples were harvested 5 minutes and 1 hour after restoration of spontaneous circulation (ROSC), and sarcoplasmic reticulum Ca²⁺ ATPase (SERCA2a), phosphorylated phospholamban (p-PLB) and rynodine receptor (RyR) were determined by Western Blot.
  
  
  RESULTS
  ROSC rate of CA group was 92.3% (24/26), and mean recovery time was (68 ± 39) seconds. Cardiac function was significantly impaired in CA group at 1 hour after resuscitation, and ejection fraction, fraction shortening (FS), the maximal rate of left ventricular pressure increase/decline (± dp/dt max) were significantly decreased compared with those in control group [ejection fraction: 0.548 ± 0.060 vs. 0.809 ± 0.043, F=71.692, P=0.000; FS: (34.4 ± 4.4)% vs. (46.0 ± 3.5)%, F=55.443, P=0.000; + dp/dt max (mmHg/s): 4 718 ± 43 vs. 7 098 ± 394, P<0.01; - dp/dt max (mmHg/s): -3 824 ± 612 vs. -6 187 ± 473, P<0.01]. Compared with control group, the expression levels of p-PLB (gray value) was significantly decreased at 5 minutes and 60 minutes (5 minutes: 0.64 ± 0.15 vs. 1.29 ± 0.13, P<0.01; 60 minutes: 0.95 ± 0.08 vs. 1.30 ± 0.09, P<0.05) after resuscitation in CA group, while the level of sarcoplasmic SERCA2a (gray value) and RyR (gray value) showed no significant differences (SERCA2a 5 minutes: 1.01 ± 0.18 vs. 1.24 ± 0.07, 60 minutes: 1.03 ± 0.14 vs. 1.25 ± 0.06; RyR 5 minutes: 0.96 ± 0.13 vs. 0.97 ± 0.13, 60 minutes: 0.88 ± 0.14 vs. 0.99 ± 0.11, all P>0.05).
  
  
  CONCLUSIONS
  The impairment of the p-PLB is closely related to postresuscitation myocardial dysfunction.
authors.affiliation: Department of Critical Care Medicine, the Third People's Hospital of Chengdu/Second Affiliated Hospital of Chengdu, Chongqing Medical University, Chengdu 610031, Sichuan, China, Corresponding author: He Qing, Email: 123hq@163.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.forename: Qing
authors.initials: Q
authors.lastname: He
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D016887:Cardiopulmonary Resuscitation; D006323:Heart Arrest / Q000628:therapy*; D006439:Hemodynamics; D008297:Male; D009206:Myocardium / Q000473:pathology*; D010766:Phosphorylation; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism*; D000099211:Phospholamban
chemical_list: D002135:Calcium-Binding Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban; C506948:Atp2a2 protein, rat