enflurane nonhuman 28 article 26 mouse 26 controlled study 24 isoflurane 24 animal experiment 22 enzyme activity 22 Enflurane 20 Mice 20 male 20 priority journal 18 5 aminolevulinate synthase 16 Isoflurane 16 Animals 14 Liver 14 Male 14 anesthesia 14 heme 14 5-Aminolevulinate Synthetase 12 Heme 12 animal tissue 12 metabolism 12 Animalia 10 allylisopropylacetamide 10 animal model 10 heme oxygenase 10 heme synthesis 10 intraperitoneal drug administration 10 Brain 8