Using a rat model of incomplete cerebral ischemia the effects of isoflurane (iso) and methohexital (metho) were compared with those of 70% nitrous oxide controls (N2O). Two levels of incomplete cerebral ischemia were produced by right carotid occlusion plus hypotension for 30 min: moderate = 30 mmHg, FIO2 = 0.30; severe = 25 mmHg, FIO2 = 0.20. The iso doses (1 and 2 MAC) and metho doses (0.01 and 0.1 mg.kg-1.min-1) were tested at each ischemic level. These iso and metho doses were selected because without ischemia they produced similar decreases in cerebral oxygen consumption (CMRO2) compared with that produced in N2O controls. In the absence of ischemia, the electroencephalogram (EEG) was suppressed by 0.01 mg.kg-1.min-1 metho and 1 MAC iso and showed burst-suppression with 0.1 mg.kg-1.min-1 metho and 2 MAC iso. The EEG was further depressed by ischemia under all anesthetic conditions. Neurologic outcome was evaluated for 3 days following incomplete cerebral ischemia by using a graded deficit score (0 = normal, 5 = death associated with stroke). Following moderate ischemia all four anesthetic treatments improved outcome compared with N2O controls, but after severe ischemia only 2 MAC iso significantly improved outcome. Neurohistopathology was evaluated on a scale of 0 to 40, 24 h after ischemia. The neurohistopathology score was significantly improved by all four anesthetic treatments compared with N2O following moderate ischemia and was better with 2 MAC iso compared with 0.1 mg.kg-1.min-1 metho after both moderate and severe ischemia. These results show that both iso and metho improve outcome from cerebral ischemia compared with that associated with N2O, but only 2 MAC iso resulted in an improved outcome following severe ischemia. This difference in outcome between the two anesthetics may be related to greater neuronal depression with iso, which may occur with little difference in cerebral metabolic depression.
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http://dx.doi.org/10.1097/00000542-199001000-00016 | DOI Listing |
Animals (Basel)
November 2024
Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, 35413 Arucas, Spain.
Vet Anaesth Analg
June 2024
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China; Nanjing Agricultural University Veterinary Teaching Hospital, Nanjing, Jiangsu, China. Electronic address:
Objective: To investigate the effect of three different doses of oral pregabalin on minimum alveolar concentration of isoflurane (MAC) in cats.
Study Design: Prospective, randomized, placebo-controlled, blinded, crossover trial.
Animals: A group of eight healthy adult cats aged 24-48 months.
Vet Res Commun
June 2024
Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, SP, 13635-900, Brazil.
The aim of this study was to determine the minimum anesthetic concentration of isoflurane (MAC) and sevoflurane (MAC) and evaluate the cardiorespiratory changes induced by varying fractions of inspired oxygen (FiO) in Magellanic penguins (Spheniscus magellanicus). Twenty adult penguins (3.53 ± 0.
View Article and Find Full Text PDFEur J Pharmacol
February 2024
School of Kinesiology, Shanghai University of Sport, Shanghai, China. Electronic address:
Aims: To investigate the cardioprotective mechanism of exercise or exercise combined with inducible costimulatory molecules (ICOS) monoclonal antibody (mAb) therapy against isoproterenol (ISO)-induced cardiac remodeling.
Main Methods: Totally 24 male C57BL/6J mice were randomly divided into four groups: the control group (normal saline treatment), ISO group (subcutaneous injection of isoproterenol, 10 mg/kg/day, once daily for 5 consecutive days), the exercise with subcutaneous ISO injection group (EPI), and the exercise with injected with ISO and ICOS mAb group (EPII). The mice in EPI and EPII group were trained on a small animal treadmill for 4 weeks (13 m/min, 0% grade, 60min/day).
Heliyon
July 2023
Department of Mathematics, School of Advances Sciences, Vellore Institute of Technology, Vellore, 632014, India.
A mathematical model is presented to analyze the magnetohydrodynamic (MHD) convective flow in a rectangular enclosure. Earlier studies on the Tiwai-Das volume fraction nanofluid model the Buongiorno nanofluid model. This is the focus of the present analysis which examines the .
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