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目的 研究氯沙坦对钠欲的影响作用及机制.方法 给予双侧杏仁中央核插管大鼠禁水24 h后自由饮水2h处理,或皮下联合注射呋塞米与卡托普利处理,以诱导其成为摄钠模型大鼠.给摄钠模型大鼠双侧杏仁中央核内联合注射0.9％ NaC1、[D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin(DAMGO)0.25μL·nmol-1和氯沙坦5 nL· nmol-1,实验分为4组:0.9％ NaCl+ 0.9％ NaCl(空白组)、0.9％NaCl+DAMGO(实验组)、0.9％ NaCl+氯沙坦(对照组)和氯沙坦+ DAMGO(联合组).用摄食-摄水-活动度分析仪分别记录摄钠模型大鼠在杏仁中央核注射后15,30,45,60,90,120,150,180,210,240 min时的0.3mol·L-1 NaCl和水的非累积摄入量(双瓶测试).结果 在禁水后不完全补水所诱导的摄钠模型大鼠,整个钠欲测试期(240 min)累积的总的摄钠量,空白组、实验组、对照组和联合组大鼠分别是(2.01 ±0.32),(8.04±1.67),(1.75 ±0.31),(4.26±0.60) mL,累积的总的摄水量分别是(2.66±0.66),(10.40±2.69),(2.15±0.46),(5.34 ±0.91)mL;与空白组相比,实验组摄钠量和摄水量都明显增加,差异均有统计学意义(均P＜0.05);与实验组相比,联合组摄钠量和摄水量都显著降低,差异均有统计学意义(均P ＜0.05).在皮下联合注射呋塞米与卡托普利所诱导的摄钠模型大鼠,整个钠欲测试期累积的总的摄钠量,空白组、实验组、对照组和联合组大鼠分别是(4.36±0.16),(9.42 ±2.02),(2.81±0.76),(5.48±1.56) mL,累积的总的摄水量分别是(8.38±0.73),(12.20±1.28),(7.05±0.52),(9.42±1.24) mL;与空白组相比,实验组摄钠量和摄水量都明显增加,差异均有统计学意义(均P ＜0.05);与实验组相比,联合组摄钠量和摄水量都显著降低,差异均有统计学意义(均P＜0.05).结论 氯沙坦在中枢能抑制杏仁中央核μ-阿片受体系统所介导的钠欲表达,脱钠大鼠钠盐摄入减少.“,”Objective To investigate the effect of losartan on sodium appetite and its underlying mechanisms.Methods Sprague-Dawley rats,with stainless steel cannulas implanted bilaterally into the central nucleus of amygdala (CeA),were treated with water deprivation for 24 h followed voluntary drinking-water for 2 h or treated with furosemide combined with captopril injected subcutaneously in order to induce to be Na + ingestion models.The Na + ingestion models of rat were received bilateral injections of combinations of saline,[D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO) 0.25 μL · nmol-1 and losartan 5 nL · nmol-1 into the CeA,and the rats were randomly assigned to four groups:saline + saline (blank group),saline + DAMGO (experimental group),losartan + saline (control group),or losartan + DAMGO (combination group).Following the CeA injections,non-cumulative 0.3 mol · L-1 NaCl intake and water intake were automatically recorded by feeding-drinking-activity analyser at 15,30,45,60,90,120,150,180,210 and 240 min (two-bottle test).Results In rats treated with water deprivation followed partial rehydration,over the entire 240 min sodium appetite tests,the cumulative total 0.3 mol · L-1 NaCl intake in blank group,experimental group,control group,and combination group were (2.01 ± 0.32),(8.04 ± 1.67),(1.75 ± 0.31),(4.26 ± 0.60) mL,respectively;the cumulative total water intake were (2.66 ± 0.66),(10.40 ± 2.69),(2.15 ±0.46),(5.34 ± 0.91) mL,respectively.Compared with the blank group,both the cumulative total NaCl intake and water intake in the experimental group increased significantly (both P ＜ 0.05).Compared with the experimental group,both the cumulative total NaC1 intake and water intake in the combination group decreased significantly (both P ＜ 0.05).In rats treated with subcutaneous injections of furosemide combined with captopril,over the entire 240 min sodium appetite tests,the cumulative total 0.3 mol · L-1 NaC1 intake in blank group,experimental group,control group,and combination group were (4.36 ±0.16),(9.42 ±2.02),(2.81 ±0.76),(5.48 ± 1.56) mL,respectively;the cumulative total water intake were (8.38 ± 0.73),(12.20 ± 1.28),(7.05 ± 0.52),(9.42 ± 1.24) mL,respectively.Compared with the blank group,both the cumulative total NaC1 intake and water intake in the experimental group increased significantly (both P ＜ 0.05).Compared with the experimental group,both the cumulative total NaC1 intake and water intake in the combination group decreased significantly (both P ＜ 0.05).Conclusion Losartan in the brain may decrease the expression of sodium appetite mediated by μ-opioid receptor system within the CeA,and then inhibits high sodium consumption by sodium-depleted rats.