Isoflurane is a suitable alternative to ether for anesthetizing rats prior to euthanasia for gene expression analysis

Area of Science:

• Toxicogenomics
• Anesthesiology
• Pharmacology

Background:

• Diethyl ether (ether) was a common anesthetic for rat euthanasia in Japan.
• Ether poses risks due to its explosive properties and toxicity.
• The Toxicogenomics Project (TGP) requires an anesthetic consistent with existing ether data.

Purpose of the Study:

• To evaluate isoflurane and pentobarbital as alternatives to diethyl ether for rat anesthesia in toxicogenomics.
• To compare the effects of these anesthetics on hematological, serum biochemical, and gene expression profiles.
• To identify an anesthetic that ensures consistency with historical TGP data.

Main Methods:

• Rats were anesthetized using diethyl ether, isoflurane, or pentobarbital.
• Hematological and serum biochemical parameters were analyzed.
• Gene expression in liver and lung tissues was assessed.
• Bioinformatic analyses (gene ontology, pathway, enrichment) were performed.

Main Results:

• No significant differences were observed in hematological or serum biochemical parameters among the three anesthetics.
• Four differentially expressed genes were identified in the liver, but pathway analyses yielded no significant relationships.
• Minimal gene expression changes were found in the lung, contrary to expectations for inhaled anesthetics.

Conclusions:

• Diethyl ether, isoflurane, and pentobarbital exhibit comparable effects on key physiological and molecular markers in rats.
• Isoflurane is recommended as a safer and suitable alternative anesthetic for rat euthanasia in toxicogenomics studies.
• Isoflurane's minimal impact on existing data ensures continuity in toxicogenomics research.