title: In vivo non-invasive quantification of muscle damage following a single intramuscular injection of phenylbutazone in sheep.
abstract: Intramuscular drug administration can lead to more or less extensive muscle damage. The aim of the present study was to show the possibility of quantitating, in vivo and non-invasively, the equivalence of muscle destroyed by the administration of a test drug (phenylbutazone) known for its injurious properties. Creatine kinase (CK) kinetic parameters (clearance, volume of distribution) were measured in 6 sheep after an iv administration of muscle CK homogenate. In the same 6 sheep, CK release after iv and im 8 mg phenylbutazone/kg was measured. The calculated total CK released, based on the CK plasma clearance (0.28 mL/kg/min) and area under the curve of CK activity after im phenylbutazone administration was 191 +/- 140 U/kg. By relating this quantity to that of CK gluteal muscle (5114 +/- 891 U/g), it was calculated that im phenylbutazone administration was able to destroy an equivalence of 2.4 +/- 2.1 g of muscle. For the 2 main sites of im administration (neck and gluteal muscle), general equations are proposed to calculate the equivalence of muscle destroyed in sheep when only plasma CK activity following a test drug administration is available.
authors.affiliation: Departement de Physiopathologie, Ecole Nationale Veterinaire, Toulouse, France.
authors.forename: P
authors.initials: P
authors.lastname: Houpert
authors.forename: J P
authors.initials: JP
authors.lastname: Serthelon
authors.forename: H P
authors.initials: HP
authors.lastname: Lefebvre
authors.forename: P L
authors.initials: PL
authors.lastname: Toutain
authors.forename: J P
authors.initials: JP
authors.lastname: Braun
mesh_terms: D000818:Animals; D002081:Buttocks; D003402:Creatine Kinase / Q000097:blood / Q000378:metabolism*; D005260:Female; D007273:Injections, Intramuscular / Q000009:adverse effects / Q000662:veterinary*; D007275:Injections, Intravenous / Q000662:veterinary; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000201:enzymology; D009334:Neck Muscles / Q000187:drug effects; D010653:Phenylbutazone / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D012756:Sheep
chemical_list: D003402:Creatine Kinase; D010653:Phenylbutazone