中国地方病学杂志
中國地方病學雜誌
중국지방병학잡지
CHINESE JOURNAL OF ENDEMIOLOGY
2011年
3期
239-242
,共4页
氟化物中毒%脑%尼古丁受体%学习%记忆
氟化物中毒%腦%尼古丁受體%學習%記憶
불화물중독%뇌%니고정수체%학습%기억
Fluoride poisoning%Brain%Nicotinic acetylcholine receptors%Learning%Memory
目的 观察燃煤型氟中毒大鼠学习记忆能力变化,测定大鼠脑组织神经型尼古丁受体(nAChR)mRNA和蛋白表达水平,探讨大鼠学习记忆能力改变的发生机制.方法 健康SD大鼠24只,体质量100～120 g,按体质量随机分为3组,每组8只.对照组饲以常规饲料,低氟组和高氟组以燃煤型氟中毒重病区燃煤烘烤的当地玉米为主要饲料(含氟量分别为11.30、104.20 mg/kg)来复制慢性氟中毒大鼠模型,染氟时间为6个月.染氟结束后,用Morris水迷宫方法检测大鼠行为学变化,处死动物取脑,用匀浆-氟离子选择电极法测定脑组织含氟量,实时荧光定量PCR法检测nAChR mRNA水平,蛋白印迹法测定nAChR蛋白表达水平.结果 低氟组和高氟组大鼠逃避潜伏期时间[(12.42±8.03)、(17.48±8.05)s]较对照组[(7.04±3.29)s]显著延长(P均<0.05),高氟组第7天穿过平台次数[(1.62±0.87)次]和逗留平台象限时间[(16.70±5.02)s]较对照组[(3.53±1.67)次、(23.33±5.35)s]降低(P均<0.05).低氟组和高氟组大鼠脑组织含氟量[(1.14±0.04)、(1.79±0.04)mg/kg]显著高于对照组[(0.52±0.05)mg/kg,P均<0.05],且高氟组大鼠脑组织含氟量高于低氟组(P<0.05).高氟组大鼠脑组织nAChR α3、α4、α7亚单位mRNA水平(1.51±0.20、1.45±0.06、1.63±0.08)较对照组(1.79±0.11、1.66±0.14、1.83±0.06)显著降低(P均<0.05),而低氟组(1.65±0.17、1.59±0.09、1.71±0.03)与对照组比较无明显改变(P均>0.05).低氟组和高氟组大鼠脑组织nAChR α3、α4、α7亚单位蛋白表达水平(0.58±0.13、0.16±0.03、1.41±0.38和0.56±0.23、0.08±0.02、0.51±0.16)较对照组(1.48±0.42、0.57±0.21、2.56±0.26)显著降低(P<0.05或<0.01).结论 燃煤型氟中毒大鼠学习记忆能力降低可能与脑组织nAChR蛋白表达及mRNA水平降低有关,nAChR表达改变可能是引起动物学习记忆能力降低的主要机制.
目的 觀察燃煤型氟中毒大鼠學習記憶能力變化,測定大鼠腦組織神經型尼古丁受體(nAChR)mRNA和蛋白錶達水平,探討大鼠學習記憶能力改變的髮生機製.方法 健康SD大鼠24隻,體質量100～120 g,按體質量隨機分為3組,每組8隻.對照組飼以常規飼料,低氟組和高氟組以燃煤型氟中毒重病區燃煤烘烤的噹地玉米為主要飼料(含氟量分彆為11.30、104.20 mg/kg)來複製慢性氟中毒大鼠模型,染氟時間為6箇月.染氟結束後,用Morris水迷宮方法檢測大鼠行為學變化,處死動物取腦,用勻漿-氟離子選擇電極法測定腦組織含氟量,實時熒光定量PCR法檢測nAChR mRNA水平,蛋白印跡法測定nAChR蛋白錶達水平.結果 低氟組和高氟組大鼠逃避潛伏期時間[(12.42±8.03)、(17.48±8.05)s]較對照組[(7.04±3.29)s]顯著延長(P均<0.05),高氟組第7天穿過平檯次數[(1.62±0.87)次]和逗留平檯象限時間[(16.70±5.02)s]較對照組[(3.53±1.67)次、(23.33±5.35)s]降低(P均<0.05).低氟組和高氟組大鼠腦組織含氟量[(1.14±0.04)、(1.79±0.04)mg/kg]顯著高于對照組[(0.52±0.05)mg/kg,P均<0.05],且高氟組大鼠腦組織含氟量高于低氟組(P<0.05).高氟組大鼠腦組織nAChR α3、α4、α7亞單位mRNA水平(1.51±0.20、1.45±0.06、1.63±0.08)較對照組(1.79±0.11、1.66±0.14、1.83±0.06)顯著降低(P均<0.05),而低氟組(1.65±0.17、1.59±0.09、1.71±0.03)與對照組比較無明顯改變(P均>0.05).低氟組和高氟組大鼠腦組織nAChR α3、α4、α7亞單位蛋白錶達水平(0.58±0.13、0.16±0.03、1.41±0.38和0.56±0.23、0.08±0.02、0.51±0.16)較對照組(1.48±0.42、0.57±0.21、2.56±0.26)顯著降低(P<0.05或<0.01).結論 燃煤型氟中毒大鼠學習記憶能力降低可能與腦組織nAChR蛋白錶達及mRNA水平降低有關,nAChR錶達改變可能是引起動物學習記憶能力降低的主要機製.
목적 관찰연매형불중독대서학습기억능력변화,측정대서뇌조직신경형니고정수체(nAChR)mRNA화단백표체수평,탐토대서학습기억능력개변적발생궤제.방법 건강SD대서24지,체질량100～120 g,안체질량수궤분위3조,매조8지.대조조사이상규사료,저불조화고불조이연매형불중독중병구연매홍고적당지옥미위주요사료(함불량분별위11.30、104.20 mg/kg)래복제만성불중독대서모형,염불시간위6개월.염불결속후,용Morris수미궁방법검측대서행위학변화,처사동물취뇌,용균장-불리자선택전겁법측정뇌조직함불량,실시형광정량PCR법검측nAChR mRNA수평,단백인적법측정nAChR단백표체수평.결과 저불조화고불조대서도피잠복기시간[(12.42±8.03)、(17.48±8.05)s]교대조조[(7.04±3.29)s]현저연장(P균<0.05),고불조제7천천과평태차수[(1.62±0.87)차]화두류평태상한시간[(16.70±5.02)s]교대조조[(3.53±1.67)차、(23.33±5.35)s]강저(P균<0.05).저불조화고불조대서뇌조직함불량[(1.14±0.04)、(1.79±0.04)mg/kg]현저고우대조조[(0.52±0.05)mg/kg,P균<0.05],차고불조대서뇌조직함불량고우저불조(P<0.05).고불조대서뇌조직nAChR α3、α4、α7아단위mRNA수평(1.51±0.20、1.45±0.06、1.63±0.08)교대조조(1.79±0.11、1.66±0.14、1.83±0.06)현저강저(P균<0.05),이저불조(1.65±0.17、1.59±0.09、1.71±0.03)여대조조비교무명현개변(P균>0.05).저불조화고불조대서뇌조직nAChR α3、α4、α7아단위단백표체수평(0.58±0.13、0.16±0.03、1.41±0.38화0.56±0.23、0.08±0.02、0.51±0.16)교대조조(1.48±0.42、0.57±0.21、2.56±0.26)현저강저(P<0.05혹<0.01).결론 연매형불중독대서학습기억능력강저가능여뇌조직nAChR단백표체급mRNA수평강저유관,nAChR표체개변가능시인기동물학습기억능력강저적주요궤제.
Objective To observe the learning and memory changes in coal-burning type of fluorosis rats, detect the expressions of neuronal nicotinic acetylcholine receptor(nAChR) at mRNA and protein levels in rat brains and to reveal the mechanism of changed learning and memory ability. Methods Twenty-four healthy SD rats, weighting 100 - 120 g, were randomly divided into three groups(8 in each). Control group was fed with normal diet, and low- and high-dose fluoride groups were fed with corn polluted with high fluoride (fluoride were 11.30,104.20 mg/kg, respectively) during drying processes with local burning-coal from the areas of endemic fluorosis to established rat model of chronic fluorosis. After exposed to fluoride for 6 months, behavioral changes were measured by Morris water maze. Animals were sacrificed, the brain was taken, after homogenizing the fluoride content of brain tissue was determined by fluoride ion selective electrode. The α3, α4 and α7 nAChR subunits at mRNA and protein levels were analyzed by real-time PCR and Western blotting, respectively. Results For rats in low- and high-fluoride groups, the escape latency time[(12.42 ± 8.03),(17.48 ± 8.05)s] was significantly longer than that in the control[(7.04 ± 3.29)s, all P< 0.05]. For rats in high-fluoride group, the numbers of crossing the platforms (1.62 ± 0.87) and the time of staying at the platforms[(16.70 ± 5.02)s] were significantly decreased as compared to that of control[3.53 ± 1.67, (23.33 ± 5.35)s, all P < 0.05]. The fluoride content in rat brain tissue in low- or high-fluoride groups [(1.14 ± 0.04), (1.79 ± 0.04)mg/kg] was significantly higher than that of control [ (0.52 ± 0.05) mg/kg, all P < 0.05]; in addition, the amount of fluoride in brain tissue of high-fluoride group was significantly higher than that of low-fluoride group(P < 0.05). In high-fluoride group, the mRNA expressions of α3, α4 and α7 nAChR subunits in rat brains(1.51 ± 0.20,1.45 ± 0.06,1.63 ± 0.08) were significantly lower as compared to controls (1.79 ± 0.11,1.66 ± 0.14,1.83 ± 0.06, all P< 0.05); whereas there were no significant changes in mRNA levels of these receptor subunits of the rat brains between low-fluoride group(1.65 ± 0.17,1.59 ± 0.09,1.71 ± 0.03) and controls (all P > 0.05). Furthermore, the protein levels of α3, α4 and α7 nAChR subunits in rat brains of highfluoride group(0.58 ± 0.13,0.16 ± 0.03,1.41 ± 0.38) and low-fluoride group(0.56 ± 0.23,0.08 ± 0.02,0.51 ± 0.16) were significantly lower than those of controls( 1.48 ± 0.42,0.57 ± 0.21,2.56 ± 0.26, P<0.05 or < 0.01). Conclusions Decreased ability of learning and memory in coal-burning type of fluorosis rats may be associated with declined expressions of nAChR at proteins and mRNA levels, which might be the main mechanism of the behavior change.
