Blood biochemistry and hematological changes in rats after administration of a mixture of three anesthetic agents

Currently, given the concerns regarding animal welfare, it is required that anesthesia or analgesia be used during surgery in experimental animals. Therefore, it is important to understand how anesthesia affects the health conditions of experimental animals. In this study, rat blood biochemistry and hematological changes were examined following administration of a mixture of three anesthetic agents-medetomidine, midazolam and butorphanol (MMB). One of three MMB dose combinations was subcutaneously administered to rats. After 1 hr, rats were treated with atipamezole, to reverse the anesthetic effects. Blood biochemistry and hematological parameters were assessed at 1, 4 and 24 hr post-MMB treatment. We also recorded body weight and food intake at 0, 2, 4, 6 and 24 hr post-MMB administration. Following MMB administration, transient increases were observed in glucose (GLUC) levels, hematocrit (HCT) values and hemoglobin (HGB) levels, whereas transient decreases were observed in total protein (TP) content and white blood cell (WBC) counts. Most of these parameters returned to control values 24 hr following MMB administration. Additionally, body weight and food intake decreased in MMB-treated rats. In conclusion, intermediate and high doses of MMB changed some blood biochemistry and hematological parameters, body weight and food intake. In contrast, low-dose MMB did not cause these effects. Therefore, depending on the experimental design, MMB may influence the results of studies that use laboratory animals. Consequently, anesthetic agents used in laboratory animals should be chosen based on detailed knowledge of their pharmacological effects.