Short-term hypoxic states can influence the health and life activities of lowlanders who travel shortly to high altitudes, in transitory situations, such as surgical ischemia-reperfusion (to one or several organs), and in some sporting activities, such as parachuting and extreme skiing, mountain rescue teams, regular commercial flight crews, in which the subject may not even notice the hypoxia. NO is an integral part of the human physiological response to hypoxia. Until recently, the urea cycle (UC) was only considered as an important mechanism for neutralizing ammonia. We are the first to reveal an interrelation in hypoxic states between the activities of NO-synthase and UC enzymes in male rats' liver, kidney and brain. In the presented work, we have shown that during short-term intermittent hypobaric hypoxia (IHH) all enzymes of UC play an important role in the maintenance of NO quantity. The results allow thinking that kidney and brain argininosuccinate synthase (ASS) and argininosuccinate lyase (ASL) and liver ASS and ASL can be different isoenzymes. It is worth mentioning that the results have revealed new sides of l-arginine metabolism in a hypoxic state in male rats.

短期缺氧状态会影响短期前往高海拔地区的低地人的健康和生活活动，在短暂的情况下，例如手术缺血再灌注（对一个或多个器官）以及一些体育活动，例如跳伞和极限运动。滑雪、山地救援队、普通的商业飞行机组，其中受试者甚至可能不会注意到缺氧。NO 是人体对缺氧生理反应的一个组成部分。直到最近，尿素循环 (UC) 才被认为是中和氨的重要机制。我们首次揭示了雄性大鼠肝脏、肾脏和大脑中 NO 合酶和 UC 酶活性之间在缺氧状态下的相互关系。在呈现的作品中，我们已经表明，在短期间歇性低压缺氧 (IHH) 期间，UC 的所有酶在维持 NO 数量方面都发挥着重要作用。结果允许认为肾脏和大脑精氨琥珀酸合酶 (ASS) 和精氨琥珀酸裂解酶 (ASL) 以及肝脏 ASS 和 ASL 可以是不同的同工酶。值得一提的是，结果揭示了新的一面雄性大鼠缺氧状态下的l-精氨酸代谢。