RADIOIMMUNE AND RADIORECEPTOR STUDY OF THE PHARMACOKINETICS OF THE ENKEPHALIN ANALOG DALARGIN IN MAN

The aim of this investigation was to study the pharmacokinetics of dalargin in many by combined use of radioimmune and radioreceptor methods. To study the pharmacokinetics of dalargin, an antiserum not cross-reacting with enkephalins or with various fragments and analogs of dalargin was used. Dalargin was iodinated with the aid of chloramine, and labeled peptide was separated from free iodine by gel-filtration with the use of Bio-Gel P-2. Radioreceptor analysis was carried out with a preparation of lyophilized rat brain membranes containing opiate receptors. To 300 microliters of membrane suspension were added 200 microliters of blood plasma, diluted, 50 microliters of /sup 3/H-D-Ala/sup 2/, and D-Leu/sup 5/-enkephalin.