Survival Under Hypoxia. Age Dependence and Effect of Cholinergic Drugs
Survival Under Hypoxia. Age Dependence and Effect of Cholinergic Drugs
复制标题
缺氧下的生存。
作者：
A. Scremin;O. Scremin;T. Brechner
在1天至50周龄的小鼠中测试缺氧（5%O2; 95%N2）下的存活率。存活率（在5% O2下存活30 mln的动物数量与暴露动物总数的比值）和从暴露开始到最后一次喘息的时间（存活时间）在新生动物中最大，并随年龄而下降。影响胆碱能传递的药物对存活率和存活时间有很大影响。阿托品以剂量相关方式降低1周龄小鼠的高缺氧存活率。毒扁豆碱可增加3 ~ 50周龄小鼠在缺氧条件下的存活率。这种作用与药物的外周作用无关，因为新斯的明（一种无中枢作用的胆碱酯酶抑制剂）不能模拟这种作用。此外，外周胆碱能阻滞剂格隆溴铵，季铵胆碱能阻滞剂，并没有阻止毒扁豆碱的保护作用。由于阿托品损害的能力非常年轻的小鼠生存缺氧和毒扁豆碱提高生存在以后的年龄，它的结论是中央胆碱能机制，可能与血流调节，在急性适应缺氧中起着重要的作用。
Survival under hypoxia (5% O2; 95% N2) was tested in mice 1 day to 50-weeks-old. Survival Rate (ratio of number of animals that survived 30 mln under 5% O2 to total number of animals exposed) and the time from onset of exposure until the last gasp (Survival Time) were maximum in newborn animals and decreased as a function of age. Survival Rate and Surviral Time were strongly influenced by drugs affecting cholinergic transmission. Atropine decreased the high survival under hypoxia of 1-week-old mice in a doserelated manner. Physostigmine increased surviral under hypoxia in mice 3 to 50-weeks-old. This effect was not related to a peripheral action of the drug since it was not mimicked by neostigmine, a cholinesterase inhibitor without central actions. Moreover, peripheral cholinergic blockade with glycopyrrolate, a quaternary cholinergic blocker, did not prevent the protective effect of physostigmine. Since atropine impairs the ability of very young mice to survive hypoxia and physostigmine improves survival at later ages, it is concluded that a central cholinergic mechanism, possibly related to blood flow regulation, plays a significant role in the acute adaptation to hypoxia.