title: Des-enkephalin-gamma-endorphin (DE gamma E): pharmacokinetics in dogs after intravenous and subcutaneous administration.
abstract: After intravenous dosing in dogs [3H-Lys9]-DE gamma E (Org 5878) was very rapidly eliminated from the circulation. Disappearance of the neuropeptide from blood followed a biphasic decay with half-lives of 0.6 +/- 0.1 min (+/- S.D.; alpha-phase) and 2.4 +/- 1.0 min (beta-phase). The central volume of distribution ranged between 0.05 and 0.23 l.kg-1. The mean blood clearance rate amounted to 0.15 l.min-1.kg-1, which is indicative of extensive hepatic and extrahepatic metabolism of DE gamma E. In contrast to intravenous dosing, subcutaneous injection of [3H]-DE gamma E in dogs resulted in low but relatively long-lasting peptide levels in blood. Peak values were found at 5-10 min, whereafter they declined to the limit of detection at 1.5-2 h. The bioavailability of DE gamma E for this route of administration was shown to be 20-23%.
authors.affiliation: Scientific Development Group, Organon International B.V., Oss, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
authors.forename: H M
authors.initials: HM
authors.lastname: van den Wildenberg
mesh_terms: D000818:Animals; D001682:Biological Availability; D004285:Dogs; D005260:Female; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D012737:Sex Factors; D013056:Spectrophotometry, Ultraviolet; D001615:beta-Endorphin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D001615:beta-Endorphin; C033558:des-enkephalin-gamma-endorphin