Ionizing Radiation Impact And Significance Of The Center Of The Plasma And Myocardial Tissue-derived Bioactive Peptides

Objective:The purpose of this experiment was to observed the changes of plasma and myocardial concentrations on angiotensin(Ang II ), endothelin(ET), atrial natriuretic polypeptide(ANP) after local heart irradiation of rats, and to investigate the relationship between ANP, AngII, ET with the dose of irradiation. Methods: The Wistar rats were divided 5 groups by irradiation dose, the irradiation were performed with single dose of 20Gy, 16Gy, 11Gy, 8Gy and control group, three months after irradiation, determine the ratio of heart weight (HW/BW), the ratio of left ventricular weight, the width of left ventricular myocardial cell, and the concentrations of ANP, AngII, ET in plasma and myocardial tissue. Results:The change of heart weight ratio, and the width of left ventricular myocardial cell were 8. 3%, 4. 65%, 9. 97%, - 2. 99 % and 45. 44 % , 16. 01 % , 13. 8 %,11.98% with control group, respectively , the change of concentrations on plasma ANP, plasma ET, plasma AngII,right atria ANP, left ventricular ANP, left ventricular ET, left ventricular Angll were 38. 46%, 7. 69%, 10. 26%,-25. 64%; 50. 67 % , 24. 98 % , 19. 9 % , 1. 6 % ; 98. 06 % , 26. 28 % , 10. 29 %, 13. 43%; -31. 75%, -21. 46%, -26. 24%, -10. 42%; 274. 7 %, 108%, 107%, 59%; 84. 4%, 53. 2%, -20. 58%, -13. 38%; 81. 48 % , 62. 96 % , 11. 11 % , - 13. 58 % , with control group, respectively. Conclusions:1,There are relationship between the change of plasma and myocardial concentrations of ANP, AngII, ET with irradiation and delivery dose, 2, The influence of irradiation is relation to irradiation dose, the damage of 8 Gy is slight, 11Gy and 16Gy might result in someirradiation heart damage, the dose of 20Gy is beyond the dose of heart can endure, can bring serious heart damage, 3, when heart should be irradiate in chest irradiation inevitably, the dose of heart received should be under 11Gy.