THE CARDIORESPIRATORY RESPONSES TO INHALATION AND PENTOBARBITAL ANESTHESIA IN THE MOUSE

Transgenic mice experiments have become increasingly popular to research human inherited disease. However a number of Japanese researchers have difficulty with the selection of anesthesia after the classification of ketamine probably the most used anesthesia as a narcotic drug in 2006. Therefore we compared the effects of inhalation anesthesia (2% of isoflurane sevoflurane and enflurane) and intraperitoneal pentobarbital anesthesia (50 mg/kg) on the electrocardiogram (ECG) and blood oxygen saturation (SPO2) of mice. With inhalation anesthesia the heart rate (HR) and SPO2 were within an acceptable range. In contrast the HR significantly decreased after initiation of pentobarbital anesthesia and gradually returned to a low rate. Importantly pentobarbital anesthesia significantly lowered SPO2 and heart rate variability analysis showed unstable beat‑to‑beat intervals during pentobarbital anesthesia suggesting that inhalation anesthesia is more suitable for evaluation of cardiorespiratory responses than pentobarbital anesthesia. During anesthesia propranolol a �� ‑adrenergic blocker significantly decreased heart rate. Atropine a parasympathetic blocker also significantly increased heart rate. Our data suggest that inhalation anesthesia is suitable for cardiorespiratory analysis in mice.