Effects of subchronic exposure to benzo<i>ɑ</i>pyrene on memory function and mRNA expressions of NMDA receptors in different brain regions in rats

Zhaofei LI; Shanshan Chang; Cancan Guo; Yi Lyu; Jinping Zheng

Return

Effects of subchronic exposure to benzoɑpyrene on memory function and mRNA expressions of NMDA receptors in different brain regions in rats

VernacularTitle:亚慢性染毒苯并[ɑ]芘对大鼠记忆功能及不同脑区NMDA受体表达的影响
Author: Zhaofei LI ¹ ; Shanshan CHANG ¹ ; Cancan GUO ¹ ; Yi LYU ¹ ; Jinping ZHENG ^{2
,

3}
Author Information

1. Department of Hygienic Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, China.
2. Department of Hygienic Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, China
3. Department of Public Health and Preventive Medicine, Changzhi Medical College, Changzhi, Shanxi 046000, China.
Publication Type:Experiment
Keywords: benzo[ɑ]pyrene; rat; spatial learning and memory ability; N-methyl-D-aspartate receptor; subunit
From: Journal of Environmental and Occupational Medicine 2022;39(7):804-808
CountryChina
Language:Chinese
Abstract: Background The altered expressions of hippocampal N-methyl-D-aspartate (NMDA) receptors induced by benzo[ɑ]pyrene (BaP) causes short-term spatial learning and memory impairment in humans and animals, but whether BaP causes alterations of NMDA receptor subunits in other brain regions and the associated neurotoxic mechanism is still essentially unknown. Objective To observe the mRNA expressions of NR1, NR2A, and NR2B of NMDA receptor subunits in different brain regions in SD rat model with subchronic exposure to BaP, and to provide a basis for in-depth study of the mechanism of BaP-induced neurotoxicity. Methods Forty male SD rats were selected and randomly divided into a control group and 1.00, 2.50, and 6.25 mg·kg⁻¹ BaP exposure groups with 10 rats in each group. The exposure rats received intraperitoneal injection of BaP every other day for 90 d.The average latency to platform, the average total distance, and the duration spent in previous quadrant were measured by the Morris Water Maze. Real-time fluorescence quantitative PCR was used to detect the mRNA expressions of NR1, NR2A, and NR2B in hippocampus, cortex, cerebellum, and striatum of rats. Results The average latency to platform and the average total distance in the 2.50 and 6.25 mg·kg⁻¹ BaP groups were significantly prolonged compared with the control group (P<0.05), and the duration that rats spent in previous quadrant in the 6.25 mg·kg⁻¹ BaP group was significantly shortened (P<0.05). Compared with the control group, the mRNA expressions of NR1 and NR2B in the hippocampus in the 2.50 and 6.25 mg·kg⁻¹ BaP groups were significantly reduced (P<0.05), and the NR2A mRNA expression in the hippocampus in the 6.25 mg·kg⁻¹ BaP group was significantly reduced (P<0.05); the mRNA expressions of NR1 and NR2B in the cortical tissue in the 6.25 mg·kg⁻¹ BaP group were significantly reduced (P<0.05), and the mRNA expression of NR2A in the cortical tissue in the 1.00 mg·kg⁻¹ BaP group was reduced; the mRNA expression of NR2B in the cerebellar tissue in the 6.25 mg·kg⁻¹ BaP group was significantly reduced (P<0.05); there were no differences in the mRNA expressions of NMDA receptor subunits in the striatum tissue (P>0.05). Conclusion Subchronic BaP exposure can cause short-term spatial learning and memory impairment in rats, which may be related to the down-regulation of mRNA expressions of NR1, NR2A, and NR2B in hippocampus, changes of mRNA expressions of NR1, NR2A, and NR2B in cortical area, and the down-regulation of NR2B mRNA expression in cerebellum.