New approaches for endorphin studies in psychiatry

Opiates are among the most powerful psychotropic drugs known. The endogenous opioids, the endorphins, are peptides with a wide distribution in the CNS. Particularly rich innervation with endorphinergic nerves is present in areas involved in sensory processing, reward and affect. Three different endorphin systems, each with a unique biosynthetic origin and equally unique neuronal distribution, are known: proopiomelanocortin derived peptides (beta-endorphin), proenkephalin A (enkephalin) and proenkephalin B (dynorphin). Each system is pluripotent, i.e. capable of releasing several chemically different opioid peptides.This article outlines the importance of distinguishing the different opioid peptide systems and different peptides species, which may differ with regard to receptor profile; most peptides interact mainly with receptors different from those activated by morphine-like opiates. This paper illustrates some methods which can be utilized. It also shows that the opioid peptide systems are amenable to studies using molecular genetics. Our current work searches for information on the turn-over rate in endorphinergic synapses by analysis of cerebrospinal fluid in patients with psychiatric disorders. We are also investigating possible genetic deficiencies by analysing the genetic material of circulating lymphocytes. CSF, Endorphins, Leukocytes, Nucleic acids, Opioid receptors, Prohormone.