The effect of concentration and duration of normobaric oxygen in reducing caspase-3 and -9 expression in a rat-model of focal cerebral ischaemia.

Abstract

The aim of this study was to determine the effect of different concentrations of normobaric oxygen (NBO) on neurological function and the expression of caspase-3 and -9 in a rat model of acute cerebral ischaemia. Sprague-Dawley rats (n=120) were randomly divided into four groups (n=30 per group), including 3 groups given NBO at concentrations of 33%, 45% or 61% and one control group given air (21% oxygen). After 2h of ischaemic occlusion, each group was further subdivided into six subgroups (n=5) during reperfusion according to the duration (3, 6, 12, 24, 48 or 72h) and concentration of NBO (33%, 45% or 61%) or air treatment. The Fluorescence Quantitative polymerase chain reaction (PCR) and immunohistochemistry were used to detect caspase-3 and -9 mRNA and protein relative expression respectively. The Neurologic Impairment Score (NIS) was significantly lower in rats given 61% NBO ≥3h after reperfusion when compared to the control group (P<0.05, Mann-Whitney U). NBO significantly reduced caspase-3 and -9 mRNA and protein expression when compared to the control group at all NBO concentrations and time points (P<0.05, ANOVA). The expression of caspase-3 and -9 was lower in the group given 61% NBO compared any other group, and this difference was statistically significant when compared to the group given 33% NBO for ≥48h and the control group (both P<0.05, ANOVA). These findings indicate that NBO may inhibit the apoptotic pathway by reducing caspase-3 and -9 expression, thereby promoting neurological functional recovery after stroke.

• Authors: Suyan Chen, Huizhen Peng, Anne Rowat, Feng Gao, Zhenxiang Zhang, Peng Wang, Weihong Zhang, Xianyuan Wang, Lixia Qu
• Journal: Brain research (Brain Res) Vol. 1618 Pg. 205-11 (Aug 27 2015) ISSN: 1872-6240 [Electronic] Netherlands
• PMID: 26032740 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• RNA, Messenger
• Caspase 3
• Caspase 9
• Oxygen

Topics

• Animals
• Brain Ischemia (therapy)
• Caspase 3 (genetics, metabolism)
• Caspase 9 (genetics, metabolism)
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Gene Expression Regulation (drug effects)
• Male
• Neurologic Examination
• Oxygen (administration & dosage)
• RNA, Messenger (metabolism)
• Rats
• Rats, Sprague-Dawley
• Statistics, Nonparametric