[New findings on endogenous drug receptor ligands].

Since the discovery of endogenous ligands for opiate receptors, endorphins and enkephalins some 30 years have elapsed. The fact that one of the breakdown products of the common precursor (proopiomelanocortin, POMC) ACTH and opioid peptides, i.e. ACTH 1-24 has a saluretic effect (balancing perhaps sodium retention after activation of the adrenal cortex) was not generally accepted yet although MSH as well as some fragments of the ACTH molecule have a natriuretic effect. The endogenous digitalis-like immunoreactive factor, DLF (even ACTH displays some DLF activities) which inhibits NaK-ATPase originates from the adrenals and is probably identical with ouabain, although I have doubts on conclusive evidence. The physiological function of DLF is not known either. Endogenous benzodiazepines ("endozepins") probably play a part in the modulation of cerebral activity: their excess may be associated with a nosological entity, idiopathic recurrent stupor. Nitric oxide, a mediator of vasorelaxing reactions, caused by acetylcholine, has already penetrated into general clinical thinking. There are at least ten diseases where NO plays a part. It is not only an endogenous factor which imitates more perfectly the action of organic nitrates but also a nervous mediator and it shares this function with another gaseous mini-hormone, carbon monoxide (CO). Endogenous ligands of drug receptors comprise also endogenous substances which interreact with receptors for calcium inhibitors (inhibitors of calcium channels). Here are important clinical perspectives not only in cardiology. There are moreover endogenous ligands for receptors for marihuana (tetrahydrocannabinols) in particular a derivative of arachidonic acid anandamide (substance of "inner bliss").(ABSTRACT TRUNCATED AT 250 WORDS)