Jihua Xin1, Yan Zhang1, Zhenzhou He1, Zhenhong Wang2. 1. Department of Anesthesiology, South Campus, Ren Ji Hospital, School of Medicine, Shanghai Jiaotong University, 2000 Jiangyue Road, Shanghai 201112, China. 2. Department of Anesthesiology, South Campus, Ren Ji Hospital, School of Medicine, Shanghai Jiaotong University, 2000 Jiangyue Road, Shanghai 201112, China. Electronic address: Zhenhong_Wang1@yeah.net.
Abstract
OBJECTIVE: To investigate the effect of salvinorin A (SA) on brain injury and neurologic function post-brain ischemia/reperfusion (I/R) using a rat forebrain ischemia model and further explore the effect of kappa opioid receptor (KOR) inhibition by SA on aquaporin-4 (AQP4) expression in the hippocampus, cortex and striatum in the forebrain. METHODS: A forebrain ischemia model was established by colligating the bilateral common carotid arteries of SD rats for 10 min. The rats were randomized to receive dimethyl sulfoxide (DMSO), SA (1 µg/100g body weight) or SA (onset of ischemia) plus SA antagonist nor-BIN (0.2 mg/100g body weight. Rat brain water content was measured. Apoptotic neurons in the hippocampal CA1 region, cortex and striatum were enumerated. AQP4 in CA1, the cortex and the striatum were determined by immunoblotting assays and immunohistochemistry at 24h post-ischemia. Neuromotor tests were performed on day 1, 2 and 5 post-ischemia. Water maze test was carried out on the 5th post-ischemia day. RESULTS: SA significantly attenuated I/R-induced increase in brain water content. Our immunoblotting assays and immunohistochemistry further revealed that SA effectively lessened I/R-induced upregulation of AQP4 expression in the hippocampus, cortex and striatum 24h post-ischemia. SA also significantly reduced the percentage of dead and apoptotic neurons in these regions compared to DMSO. Moreover, SA partially reversed I/R-induced decline in rat motor function and cognition. The neuroprotective effects of SA were partially abolished by nor-BIN. CONCLUSION: SA protects against I/R-induced brain injury by attenuating brain edema formation and inhibiting neuronal death and improves neurologic recovery of rats post-I/R.
OBJECTIVE: To investigate the effect of salvinorin A (SA) on brain injury and neurologic function post-brain ischemia/reperfusion (I/R) using a rat forebrain ischemia model and further explore the effect of kappa opioid receptor (KOR) inhibition by SA on aquaporin-4 (AQP4) expression in the hippocampus, cortex and striatum in the forebrain. METHODS: A forebrain ischemia model was established by colligating the bilateral common carotid arteries of SD rats for 10 min. The rats were randomized to receive dimethyl sulfoxide (DMSO), SA (1 µg/100g body weight) or SA (onset of ischemia) plus SA antagonist nor-BIN (0.2 mg/100g body weight. Rat brain water content was measured. Apoptotic neurons in the hippocampal CA1 region, cortex and striatum were enumerated. AQP4 in CA1, the cortex and the striatum were determined by immunoblotting assays and immunohistochemistry at 24h post-ischemia. Neuromotor tests were performed on day 1, 2 and 5 post-ischemia. Water maze test was carried out on the 5th post-ischemia day. RESULTS:SA significantly attenuated I/R-induced increase in brain water content. Our immunoblotting assays and immunohistochemistry further revealed that SA effectively lessened I/R-induced upregulation of AQP4 expression in the hippocampus, cortex and striatum 24h post-ischemia. SA also significantly reduced the percentage of dead and apoptotic neurons in these regions compared to DMSO. Moreover, SA partially reversed I/R-induced decline in rat motor function and cognition. The neuroprotective effects of SA were partially abolished by nor-BIN. CONCLUSION:SA protects against I/R-induced brain injury by attenuating brain edema formation and inhibiting neuronal death and improves neurologic recovery of rats post-I/R.
Authors: Elaine C D Gonçalves; Gabriela M Baldasso; Maíra A Bicca; Rodrigo S Paes; Raffaele Capasso; Rafael C Dutra Journal: Molecules Date: 2020-03-29 Impact factor: 4.411