Effects of PAF on isolated rat airways perfused with blood-free solution.
Effects of PAF on isolated rat airways perfused with blood-free solution.
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PAF 对灌注无血溶液的离体大鼠气道的影响。
DOI：
10.1152/ajplung.1991.260.4.l260
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Leff,AR
中科院分区：
文献类型：
--
作者：
Munoz,NM;Kirchhoff,CF;Strek,ME;Blumenthal,RN;Leff,AR
我们在组织灌注室等距灌注55只Sprague-Dawley大鼠气道中，研究了血小板活化因子（PAF）引起气道平滑肌收缩和毒蕈碱增强收缩的机制。将溶解于含有4%牛血清白蛋白的Krebs-Henseleit缓冲液中的10（-10）至10(-7)mol PAF注入BC或PC，累积生成剂量-反应曲线。PAF在中心气道（BC）增加肺阻力（RL）的效果约为PC灌注更多周围气道的两倍（P < 0.05）。在BC和PC中，对产生第二个PAF剂量-反应曲线的制剂均证明了快速反应。注射10(-6)mol PAF拮抗剂CV-6209加10(-7)mol PAF可使最大BC应答逆转81%。相同剂量的CV-6209使PC对PAF的反应逆转了99.2%。初始给药10(-6)mol CV-6209与PAF可阻止PAF引起的BC和PC的完全收缩。在组织灌注室中对64条气管平滑肌条进行了浓度-反应研究。10(-6) M PAF引起的最大收缩被10(-6)M CV-6209完全阻断。在单独的研究中，在BC灌注液中添加10(-6)mol CV-6209可阻断RL对PAF的93%的反应，在PC中给予时可抑制100%。先前给予PAF可使同一制剂中对乙酰胆碱（ACh）的收缩反应增强2 - 4倍；CV-6209存在时，对乙酰胆碱的反应没有变化。（摘要删节250字）
We examined the mechanism of constriction and muscarinic augmentation of contraction of airway smooth muscle caused by platelet-activating factor (PAF) in airways from 55 Sprague-Dawley rats perfused through the isolated bronchial circulation (BC) and pulmonary circulation (PC) and isometrically in tissue perfusion chambers. Dose-response curves were generated cumulatively by infusing 10(-10) to 10(-7) mol PAF dissolved in Krebs-Henseleit solution buffer containing 4% bovine serum albumin into the BC or PC. The efficacy of PAF in central airways (BC) was approximately twofold greater in increasing lung resistance (RL) than for more peripheral airways perfused by the PC (P less than 0.05). Tachyphylaxis was demonstrated in both BC and PC for preparations in which a second PAF dose-response curve was generated. Bolus injection of 10(-6) mol of the PAF antagonist, CV-6209, plus 10(-7) mol PAF caused 81% reversal of the maximal BC response. The same dose of CV-6209 reversed the response to PAF in the PC by 99.2%. Initial administration of 10(-6) mol CV-6209 with PAF prevented completely contraction elicited by PAF in the BC and PC. Concentration-response studies also were generated isometrically in tissue perfusion chambers from 64 tracheal smooth muscle strips. Maximal contraction elicited by 10(-6) M PAF was blocked completely with 10(-6) M CV-6209. In separate studies, addition of 10(-6) mol CV-6209 to the BC perfusate caused 93% blockade of the RL response to PAF and 100% inhibition when administered in the PC. Prior administration of PAF caused two- to fourfold augmentation of the contractile response to acetylcholine (ACh) within the same preparation; in the presence of CV-6209, the response to ACh was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)