title: Comparative pharmacokinetics of oxytetracycline in rainbow trout (Salmo gairdneri) and African catfish (Clarias gariepinus).
abstract: A comparative pharmacokinetic study was conducted in rainbow trout (Salmo gairdneri) and African catfish (Clarias gariepinus) following intravenous (i.v.) and intramuscular (i.m.) administration of oxytetracycline (OTC) at a dose rate of 60 mg/kg body weight. Trout and catfish were kept in aerated tap water in tanks at constant temperatures of 12 degrees C and 25 degrees C, respectively. The two- and three-compartment open models adequately described plasma drug disposition in African catfish and rainbow trout respectively, following i.v. OTC administration. Compared to catfish (COP = 86 +/- 10 micrograms/ml) an eightfold higher extrapolated zero time concentration was obtained in trout (COP = 753 +/- 290 micrograms/ml). A significant difference was observed with respect to the relatively large apparent distribution volumes (Vd(area] after i.v. OTC administration (trout, mean value: 2.1 l/kg; catfish, mean value: 1.3 l/kg). The mean final elimination half-lives of both fish species were greater than previously reported in mammals (trout, 89.5 h; catfish, 80.3 h). A mean maximum plasma concentration (Cmax = 56.9 micrograms/ml) was obtained in trout at 4 h after i.m. administration of OTC. In catfish a lower Cmax of 43.4 micrograms/ml was determined at about 7 h. No significant difference was observed with respect to bioavailability following i.m. administration of OTC (trout, 85%; catfish, 86%).
authors.affiliation: Department of Experimental Animal Morphology and Cell Biology, Agricultural University, Nijmegen, The Netherlands.
authors.forename: J L
authors.initials: JL
authors.lastname: Grondel
authors.forename: J F
authors.initials: JF
authors.lastname: Nouws
authors.forename: A R
authors.initials: AR
authors.lastname: Schutte
authors.forename: F
authors.initials: F
authors.lastname: Driessens
mesh_terms: D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D006207:Half-Life; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D010118:Oxytetracycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*
chemical_list: D010118:Oxytetracycline