Departments of aAnesthesiology and Pain Medicine and bPsychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA.
Pain. 2017 Dec;158(12):2290-2300. doi: 10.1097/j.pain.0000000000001043.
Before the discovery of the endogenous opioid system in the 1970s, opioids were understood only through the lens of opioid drug effects. Opium produced sleep, pain relief, and addiction. Once a variety of opioids had been extracted from opium, and still others synthesized chemically, it became clear that there must be endogenous receptors to explain differential drug effects. So, the search was on to identify the receptors, and subsequently their endogenous ligands. Even then, the consequential ways in which the endogenous opioid system influences the way we respond to the environment and survive took time to unravel. Today's understanding extends far beyond simply accepting pain relief and addiction as separate processes, to the realization that the endogenous opioid system achieves constant adjustments between punishment (pain) and reward in communicating areas of the brain previously thought to subserve separate functions. The system also plays a crucial role in socialization. Taken together, these 2 lines of research have led to new insights into why the endogenous opioid system is so important in terms of evolution, individual survival and day-to-day function, and how important it is to consider opioid medications within the context of these critical natural functions.
在 20 世纪 70 年代发现内源性阿片系统之前，人们对阿片类药物的理解仅仅局限于阿片类药物的作用。鸦片能使人入睡、止痛和成瘾。一旦从鸦片中提取出各种阿片类药物，并且通过化学方法合成其他阿片类药物，就很明显，必须有内源性受体来解释药物作用的差异。因此，人们开始寻找这些受体，以及随后发现它们的内源性配体。即使在那个时候，内源性阿片系统影响我们对环境做出反应和生存的方式的必然途径也需要时间来解开。今天的理解远远超出了简单地接受止痛和成瘾是两个独立的过程，而是认识到内源性阿片系统在大脑的通讯区域中实现了惩罚（疼痛）和奖励之间的持续调节，而这些区域以前被认为是用于不同的功能。该系统在社会化中也起着至关重要的作用。总之，这两条研究线索使人们对内源性阿片系统在进化、个体生存和日常功能方面的重要性有了新的认识，以及在这些关键的自然功能背景下考虑阿片类药物的重要性。
