Effect of Tribromoethanol‐Medetomidine Combination Anesthetic on cycling and ovariectomized Sprague‐Dawley Rats

Abstract

Tribromoethanol (TBE) and medetomidine (MT; alpha2-adrenergic agonist) combination was found to be an effective anesthetic in male rats which can be reversed by atipamezole, an alpha2-adrenergic antagonist. This study was set up to learn if this anesthetic combination would be effective in female rats as well. Study 1: Estrous cycles were monitored daily for a week. The animals were then divided into two groups of 9. On the day of the experiment, both groups received TBE (150mg/kg)-MT (0.5mg/kg) combination. Group 1 was allowed to recover spontaneously. Group 2 was given atipamezole (1mg/kg) 10 min after the anesthetic induction. The induction time for both groups was 2 min. For Group 1, the anesthetic duration was 67 min and the recovery time was 79 min and for Group 2, the reversal time was 2 min and the recovery time was 1 min. Their estrous cycles were monitored for 10 more days following the experiment and found that the cycles were uninterrupted. Study 2: Group 1 (non-ovariectomized rats, n=9) and Group 2 (ovariectomized rats, n=8) received TBE-MT combination and atipamezole 10 min postinduction. The induction time for Group 1 was 2.51 min, reversal time was 1 min and the recovery time was 0.46 min. and for Group 2, the induction time was 2.12 min, the reversal time was 1.87 min and the recovery time was 0.46 min. These results suggest that the combination anesthetic is effective in female rats, does not affect their estrous cycles, and works in ovariectomized rats.