异丙酚、氯胺酮对哮喘大鼠气道痉挛及气道渗出的作用

Propofol and ketamine attenuate antigen-induced bronchoconstriction and microvascular leakage in rats

目的 观察异丙酚、氯胺酮对抗原诱发哮喘大鼠气道痉挛及气道渗出的影响。方法哮喘大鼠30只随机分为5组:I组,静注生理盐水;Ⅱ组,静注异丙酚50 mg·kg·-1·h-1;Ⅲ组,静注异丙酚100 mg·kg-1·h-1;Ⅳ组,静注氯胺酮50 mg·kg-1·h-1;V组,静注氯胺酮100 mg·kg-1·h-1。30 min后静注伊文氏蓝;5 min后静注卵蛋白激发哮喘发作,并维持30 min。观察气道压、肺系数、肺湿干重比、肺含水量、肺组织伊文氏蓝含量变化。结果异丙酚和氯胺酮能显著缓解卵蛋白激发引起的气道痉挛反应(P<0.05),相同剂量异丙酚和氯胺酮对气道压的影响无显著性差异。异丙酚和氯胺酮均可明显降低大鼠肺系数、肺湿干重比和肺含水量(P<0.05)。静注异丙酚或氯胺酮后,肺组织伊文氏蓝渗出明显减少,与I组比较差异有显著性(P<0.05)。结论 异丙酚和氯胺酮均能缓解抗原诱发哮喘大鼠的气道痉挛,且能明显抑制哮喘大鼠的气道渗出。

Objective To investigate the effects of propofol and ketamine on antigen-induced bronehoconstriction and microvascular leakage in rats.Methods Thirty SD rats of both sees weighing 150-200 g were sensitized with ovalbumin 1 mg, aluminium hydroxide 200 mg and devitalized Bordetella pertusis (6 × 109 ) adminisered intraperitoneally 2 weeks before experiment. The animals were anesthetized with pentobarbital 30 mg · kg-1 ip, tracheotomized and mechanically ventilated (VT = 10 ml· kg-1 , RR = 70 bpm) . The animals were randomly divided into 5 groups with 6 animals in each group: group I received normal saline iv group II propofol 50 mg·kg-1·h-1 iv group III propofol 100 mg·kg-1·h-1 iv group IV ketamine 50 mg·kg-1·h-1 iv; and group V ketamine 100 mg· kg-1· h-1 iv. Two minutes after propofol or ketamine administration Evan's blue 30 mg·kg-1 was given iv. Five minutes after dye injection ovalbumin 15 mg·kg-1 was injected iv to trigger asthmatic attack which was maintained for 30 min when airway pressure was measured. Then the animals were sacrificed by bleeding. Heart and lungs were removed for determination of lung coefficient( wet lung weight/body weight) , wet lung/dry lung ratio, lung extravascular water content [ (wet lung weight - dry lung weight/wet lung weight × 100% ] and lung Evans blue content (formamide extraction method) . Results Propofol and ketamine significantly attenuated ovalbumin-induced bronchoconstiction( P < 0.05) . Both anesthetics also significantly decreased lung coefficient, wet lung/dry lung ratio and lung extravascular water content( P < 0.05) . Evan's blue content in trachea, main bronchus and bronchioles was significantly lower in propofol and ketamine groups. Propofol causes stronger inhibition of microvascular leakage than ketamine at the dose of 100 mg·kg-1·h-1 .Conclusions Both propofol and ketamine attenuate antigen-induced bronehoconstriction and microvascular leakage. Propofol is more effective than ketamine in reducing microvascular leakage.