[Effect of opiate peptides on interneuronal transmission in the spinal cord]

It has been shown that leucin- and methionine-enkephalins (200 microgram into the lateral brain ventricle), as well as synthetic opiate peptides FK 33-824 (2 mg/kg) and tetrapeptide (25 mg/kg) disturb the excitation transmission in the cat ventrolateral columns. The effects of opiate receptors was more pronounced in animals with the intact central nervous system as compared with spinal animals. Naloxone (1 mg/kg) eliminated the effect of opiate peptides.