title: Evaluation of liposome-encapsulated oxymorphone hydrochloride in mice after splenectomy.
abstract: The use of mice in biomedical research is increasing, largely due to the production and use of genetically engineered animals. Providing postoperative pain control in mice presents many challenges, and long-acting analgesic preparations would be advantageous for this species. A single subcutaneous injection of a liposome-encapsulated (LE) preparation of oxymorphone was compared with multiple injections of buprenorphine or saline in outbred mice undergoing splenectomy. Control groups were given isoflurane alone or isoflurane and an injection of LE oxymorphone but did not undergo surgery. The following parameters were evaluated for 5 days after surgery and were compared with presurgical baseline data for each group: food and water consumption, body weight, ethographic score, and voluntary exercise on a running wheel. Ethographic scores indicated less postsurgical pain in both groups of mice that received either analgesic preparation compared with mice that received only saline. However, mice given LE oxymorphone had superior postoperative recovery, as measured by wheel-running distance and body weight gain, compared with mice given buprenorphine or saline. Mice undergoing splenectomy had significant decreases in body weight, food and water consumption, voluntary exercise, and other normal behaviors. Administration of liposomal oxymorphone at the time of surgery improved postsurgical recovery as measured by these parameters compared with multiple injections of buprenorphine or saline alone. Administration of LE oxymorphone at the time of surgery improved postsurgical recovery, as measured by these parameters.
authors.affiliation: Laboratory Animal Services, 414 E. Clark St., Lee Medical Bldg., University of South Dakota, Vermillion, South Dakota 57069, USA.
authors.forename: Melanee D
authors.initials: MD
authors.lastname: Clark
authors.forename: Lisa
authors.initials: L
authors.lastname: Krugner-Higby
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Smith
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Heath
authors.forename: Krystal L
authors.initials: KL
authors.lastname: Clark
authors.forename: Dawne
authors.initials: D
authors.lastname: Olson
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D021461:Animals, Outbred Strains; D001522:Behavior, Animal / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002047:Buprenorphine / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D007279:Injections, Subcutaneous; D007756:Laboratory Animal Science / Q000379:methods*; D008081:Liposomes; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010111:Oxymorphone / Q000008:administration & dosage*; D010146:Pain / Q000517:prevention & control; D010147:Pain Measurement; D010805:Physical Conditioning, Animal; D013047:Specific Pathogen-Free Organisms; D013156:Splenectomy / Q000662:veterinary*
chemical_list: D000701:Analgesics, Opioid; D008081:Liposomes; D002047:Buprenorphine; D010111:Oxymorphone