Influence of handling procedures on rat plasma creatine kinase activity

Ten-week-old Sprague–Dawley rats were held behind the front legs before and during anesthetic injection of sodium pentobarbital (group 1, 12 rats), or lifted by the base of the tail before and during injection (group 2, 12 rats). Creatine kinase (CK) values were higher (P = 0.004) in group 1 (median 564 IU/L) than in group 2 (median 272 IU/L). Handling rats by holding them behind the front legs may reduce the usefulness of CK activity as a measure of muscular disorders. © 1999 John Wiley & Sons, Inc. Muscle Nerve 22: 1119–1121, 1999