COMPARISON BETWEEN SPRAGUE-DAWLEY AND WISTAR RATS AS AN EXPERIMENTAL-MODEL OF PHARMACOKINETIC ALTERATIONS INDUCED BY SPINAL-CORD INJURY

Two strains of rats, Sprague-Dawley and Wistar, were assayed in order to determine which strain is the more suitable experimental model for the study of pharmacokinetic alterations induced by spinal cord injury . Animals were submitted to spinal cord contusion at the T8-T9 level b y the weight drop method. A single acetaminophen oral dose (100 mg/kg) was administered 24 h after injury and blood samples were drawn for a period of 4 h. Acetaminophen concentration in whole blood was determi ned by high performance liquid chromatography and pharmacokinetic para meters were estimated. For both strains, C-max and AUC were significan tly lower, whereas t(max) remained unchanged, in injured animals compa red to sham-injured controls. Circulating acetaminophen concentrations were higher; therefore, pharmacokinetic alterations were more easily discerned, in Sprague-Dawley than in Wistar rats. It is concluded that the Sprague-Dawley strain is a more suitable model for the study of p harmacokinetic alterations induced by spinal cord injury.