Crittenden D J, Beckman D L
Life Sci. 1983 Nov 14;33(20):1959-64. doi: 10.1016/0024-3205(83)90733-6.
Previous studies have shown that sympathetic factors and blood glucose are of importance in the development of seizures and lung damage from OHP. In the present study we examined the influence of beta sympathetic agonists and blocking agents and glucagon on OHP toxicity. Rats were exposed to 6 ATA OHP and examined for time-to-seizure and lung damage. Pretreatment with propranolol increased the time-to-seizure by 70% and practolol by 50% without altering gross lung appearance or lung wet wt/dry wt. Propranolol and practolol also prevented brain glycogen depletion prior to seizure which otherwise occurred in subconvulsive exposure to OHP. Isoproterenol and glucagon pretreatment had no effect on time-to-seizure but isoproterenol did increase lung injury. Both practolol and propranolol block the beta-receptor influence on adenyl cyclase-stimulated second messenger production, while both isoproterenol and glucagon activate adenyl cyclase to produce second messenger. Our results may suggest a possible role for second messenger in mediating some of the acute toxic effects of OHP on the CNS.
先前的研究表明，交感神经因素和血糖在由高压氧（OHP）诱发的癫痫发作和肺损伤过程中具有重要作用。在本研究中，我们检测了β-交感神经激动剂、阻断剂和胰高血糖素对高压氧毒性的影响。将大鼠暴露于6个绝对大气压的高压氧环境中，并检测其癫痫发作时间和肺损伤情况。用普萘洛尔预处理使癫痫发作时间延长了70%，而用醋氨心安预处理则延长了50%，且未改变肺的大体外观或肺湿重/干重。普萘洛尔和醋氨心安还能预防癫痫发作前脑糖原的消耗，而在亚惊厥剂量的高压氧暴露中，这种消耗原本是会发生的。异丙肾上腺素和胰高血糖素预处理对癫痫发作时间没有影响，但异丙肾上腺素确实增加了肺损伤。醋氨心安和普萘洛尔均可阻断β受体对腺苷酸环化酶刺激的第二信使生成的影响，而异丙肾上腺素和胰高血糖素均可激活腺苷酸环化酶以产生第二信使。我们的结果可能提示第二信使在介导高压氧对中枢神经系统的一些急性毒性作用中可能发挥作用。
