An Experimential Study On Changes And Cilinical Significance Of CGRP,TXA₂ And PGI₂ In Plasma Of Rabbits With PTE Before And After Pulmonary Thrombolysis

Backgroud and Objectivespulmonary thromboembolism(PTE) is the most common category of the pulmonary embolism(PE) and Clinically PTE is always the term stands for PE as most of all cases of PTE belong to PE. Researches of American epidemicology show that PTE is the third cause of human death. Cardiovascolar hospital of Chinese Medical and Science department has proved that 11% of all the PTE cases were located on the segamental or the upper broncus after they did 900 autopsies. In recent years as more attention was paid to PTE and the pathophysiological and pathological developments were accelerated, the morality rose significantly. But, in China the misdiagnosis is very common and curtails the cure and the prognosis. The effective way to decrease the motality of PTE is to identify and dissolve the embolism in early stage. Howerer, the immediate treatment of PE was inhibited for there is no effective diagnostic means. So it is necessary to search for a simple way to discern PTE and evaluate the effectiveness of the treatment. Many studies show that cytokines are involved in the process of PE. Some of the cytokines which could constrict vessels are involvoled in pulmonary hypertension and the rise of others which could dilate vessels in blood proved that they take part in defensive response. The dynamic observation of these cytokines such as CGRP,TXA₂ and PGI₂ may give us indications of the tendency, the progression and the prognosis of PE. The aim of this study is to investigate changes of these cytokines and their antagonists before and after pulmonary thrombolysis and find a way to early diagnosis and effective therapy.Methods and MaterialsHealthy 30 rabbits were assigned into 3 groups randomly: control group, PE group and thrombolytic group. Method of self-comparison was used to analyse the datas. Models of PE were set up by injection of auto-blood clots into femoral vein in PE group while in control group by injection of sterile saline water and thrombolytic group by injection of urokinase. The plasma of all rabbits were exsanguinated quickly before PTE and 1,2,4, 6hours respectively after the experiment.Results1. CGRP : There is no statistical difference of plasma levels of CGRP in control group .The plasma levels of CGRP were significantly higher after 2 and 4hours of PE compared to pre-PE in PE group while significantly higher only after 2 hours in thrombolytic group.2. TXA₂: There is no statistical difference of plasma levels of TXA₂ in control group . The plasma levels of TXA₂ is were significantly higher in 2 to 4 hours of after PE compared to pre-PE in PE group but higher only after 2 hour in thrombolytic group.3. PGI₂: There is no statistical difference of plasma levels of PGI₂ in control group . The plasma levels of PGI₂ were significantly higher in 1 to 2 hour(P=0.009) after PTE in PTE group. In thrombolytic group the level of PGI₂ was significantly higher after 1 hour(P=0.009), but sharply decreased after 2 hours .Conclusions1. It is pratical and simple to prepare thromboembolus by exploiting self blood clots during short period and this blood clots may keep in pulmonary artery for at least 6 days. 2. CGRP,TXA₂ and PGI₂ is involved in pulmonary inflammation of acute PE.