目的 研究同位素⁹⁹Tc^m示蹤血栓技術(shù)在家兔腦卒中模型上的應(yīng)用，并動態(tài)示蹤觀察重組組織型纖溶酶原激活劑（rt-PA）對血栓的溶解效果。方法 將新鮮洗脫的放射性高锝酸鈉（5 mCi/2 mL，92.5 MBq/mL）0.5 mL與5 mg/mL氯化亞錫30 μL充分混合成示蹤標記液；分別向全血、紅細胞、血漿中加入20 μL示蹤標記液進行同位素標記，加入50 μL CaCl₂（0.5 mol/L）與牛凝血酶（50 IU/mL）混合物，迅速吸入聚乙烯塑料管（PE80）中，37℃固化2 h后取出血栓，分割成10 mm的示蹤血栓，并計算標記率。采用經(jīng)兔頸外動脈逆向頸內(nèi)動脈插管方法，注射示蹤血栓栓塞大腦中動脈，制備腦卒中模型，用γ計數(shù)儀在兔頭部測定放射性強度即每分鐘計數(shù)（Counts Per Minute，CPM）的動態(tài)變化，并觀察臨床等效劑量工具藥rt-PA4.5 mg/kg的溶栓效果。結(jié)果 全血血栓標記率為53.5%，紅細胞與血漿標記比率為4.5∶1，家兔大腦中動脈血栓栓塞后CPM明顯增加，約為本底的5.1±1.3倍，表明模型制備成功，檢測可靠。靜脈給予工具藥rt-PA能產(chǎn)生顯著的漸進性溶栓效果。結(jié)論 锝標記主要以標記紅細胞為主，對血漿及纖維蛋白原影響較小。⁹⁹Tc^m示蹤血栓技術(shù)制備的腦卒中模型，分離區(qū)明顯，模型制備成功、指標檢測科學，模型對藥物療效應(yīng)答能力的反應(yīng)穩(wěn)定、可靠。

Objective To study the application of ⁹⁹Tc^m in rabbit cerebral thromboembolic stroke and thrombolysis effect of recombinant tissue plasminogen activator (rt-PA). Methods The 0.5 mL radioactive pertechnetate sodium (specification: 5 mCi/2 mL and radiation intensity 92.5 MBq/mL) was combined with 30 μL stannous chloride (5 mg/mL), and the 20 μL mixture was joined to whole blood, red blood cells, and plasma for labelling. Then 50 μL CaCl₂ (0.5 mol/L) and bovine thrombin (50 IU/mL) were doped in mixture, and rapidly sucked into a polyethylene plastic pipe (PE80). Thrombus was formed for 2 h at 37 ℃ and cut into small pieces of 10 mm. Autologous blood clots combined with ⁹⁹Tc^m from external carotid artery were injected to internal carotid artery of rabbit, the radioactivity (counts per minute, CPM) was measured by gamma counting instrument, and the improvement of rt-PA 4.5 mg/kg (clinical equivalent dose) on this model was observed. Results After thromboembolism, CPM increased approximately by (5.1±1.3) times, which suggested that the model was reliable. The rt-PA 4.5 mg/kg had significant progressive thrombolysis effect. Conclusion ⁹⁹Tc^m tracer technology could be applied to rabbit cerebral stroke model, which is stable and reliable