Stereospecific opiate binding in living human polymorphonuclear leucocytes

Abstract

Living human polymorphonuclear leukocytes were incubated with various opiate agonists and antagonists in radioreceptor assays. Binding of the opiate antagonists 3H-naloxone and 3H-diprenorphine and of the benzomorphan 3H-ethylketocyclazocine was found at 4.degree.C and at 37.degree.C, 3H-naloxone binding was stereospecific. Binding of the opiate agonist 3H-dihydromorphine was present at 37.degree. C but not at 4.degree. C and had a different time course as compared to the antagonists. At both temperatures no specific binding of the proteolytic stable analogue 3H-D-Ala-D-Leu-enkephalin was found. Autoradiography showed an unspecific accumulation of 3H-naloxone inside the cells and a specific localization of grains at the cell membrane.