The endocannabinoid system

Endokanabinoidni sustav zajednički je naziv za receptore kanabinoid receptor 1 i kanabinoid receptor 2, ligande tzv. endokanabinoide anandamid i 2-arahidonoilglicerol, te enzime koji sudjeluju u njihovom metabolizmu. Naziv je dobio po biljci Cannabis sativa, čije se najvažnije aktivne tvari tetrahidrokanabinol i kanabidiol vežu za kanabinoidne receptore. Psihotropni učinak kanabisa povijesno je zasjenio ostale učinke njegovih aktivnih tvari te tako i širok spektar funkcija endokanabinoidnog sustava. Endokanabinoidni sustav ne utječe samo na psihološku i neurološku funkciju čovjeka, nego ima i ključnu funkciju u regulaciji fiziološke funkcije probavnog sustava te patologiji upale istog. Pokazalo se da je endokanabinoidni sustav ključni element u središnjem živčanom sustavu, gdje se putem njega odvija retrogradna signalizacija među neuronima. Isto tako, sudjeluje u modulaciji brojnih metaboličkih mehanizama. Danas je poznato da funkciju endokanabinoidnog sustava u užem smislu nadopunjava takozvani endokanabinoidom, skupni naziv za sve ostale receptore, ligande, enzime i metabolite svojom funkcijom povezane s endokanabinoidnim sustavom. Tako širok spektar djelovanja svojevrsni je dvosjekli mač, naime otvara mnoga vrata za terapijsku primjenu, dok istovremeno otežava istraživanje i sintezu lijekova koji bi mogli biti od praktične koristi. Naime, zbog velikog preklapanja i svestranosti nije lako sintetizirati lijekove koji će imati izolirani učinak. Bolje razumijevanje endokanabinoidnog sustava omogućit će daljnje razjašnjavanje brojnih fizioloških i patoloških procesa u ljudskom tijelu, te time potencijalno otvoriti vrata za mnoge nove terapijske metode koje će modulirati funkciju endokanabinoidnog sustava.The term endocannabinoid system is commonly used to refer to the receptors, ligands, so-called endocannabinoids and the enzymes involved in their metabolism. It is named after the plant Cannabis sativa whose most important active substances tetrahydrocannabinol and cannabidiol bind to the endocannabinoid receptors. Tetrahydrocannabinol's psychotropic effects are the main reason for the popularity of cannabis, which is the most popular recreational drug in the Western world. Early scientific research focused on the effects of tetrahydrocannabinol due to its psychotropic nature. Possibly because of the toxic effects of tetrahydrocannabinol and because of the belief that tetrahydrocannabinol is the main active substance in cannabis, early research focused primarily on the effects of tetrahydrocannabinol. Only much later, with the discovery of the endocannabinoids and the myriad of functions that the endocannabinoid system performs in the mamallian body, did the focus of research slowly drift towards the endocannabinoid system itself, as opposed to the fitocannabinoids. The bodily functions which the multifarious endocannabinoid system affects include the central nervous system, gastrointestinal system and immune system. The cannabinoid receptors CB1 and CB2 are widespread throughout the human body. As such, it is difficult to target them specifically for therapeutic purpose. Hundreds of mediators are chemically related to endocannabinoids, often with similar metabolic pathways, thus the path to therapeutic relevancy is further complicated. Better understanding of the endocannabinoid system will enable researchers to discern the exact function of many key mechanisms in the human body, an thus hopefully pave the way to new therapeutic avenues