【摘要】 目的:探讨高盐饮食对尿素通道蛋白B基因（UT-B）缺失(UT-B^-/-)小鼠动脉血压的影响,阐明UT-B^-/-导致小鼠动脉血压改变的可能机制。方法:杂合子小鼠交配获得遗传背景相同野生型(UT-B^+/+)小鼠和UT-B^-/-小鼠;选取4周龄雄性UT-B^+/+小鼠和UT-B^-/-小鼠,分别给予4周普通饮食（0.3%NaCl）或高盐饮食（8.0%NaCl）,分为UT-B^+/+小鼠+普通饮食组(UT-B^+/++N)、UT-B^-/-小鼠+普通饮食组(UT-B^-/-+N)、UT-B^+/+小鼠+高盐饮食组(UT-B^+/++H)和UT-B^-/-小鼠+高盐饮食组(UT-B^-/-+H),共4组。监测各组小鼠饮水量和平均动脉压的变化,采用RT-PCR法、Western blotting法和免疫组织化学法检测脑组织脉络丛（CP）UT-B mRNA和蛋白表达水平和定位,ELISA法检测各组小鼠血清血管紧张素Ⅱ（AngⅡ）水平和脑脊液中钠离子水平。结果:PCR法检测鼠尾基因组DNA,UT-B^+/+小鼠在400bp处有1条碱基片段,杂合子小鼠在250和400bp处各有1条碱基片段,UT-B^-/-小鼠在250bp处有1条碱基片段。与普通饮食组比较,高盐饮食组小鼠饮水量明显增加（P<0.01）;与UT-B^-/-小鼠+普通饮食组和UT-B^+/+小鼠+高盐饮食组比较,UT-B^-/-小鼠+高盐饮食组小鼠平均动脉压明显升高（P<0.01）;UT-B mRNA和蛋白表达于UT-B^+/+小鼠脑组织CP上皮细胞。与UT-B^-/-小鼠+普通饮食组和UT-B^+/+小鼠+高盐饮食组比较,UT-B^-/-小鼠+高盐饮食组小鼠血清AngⅡ水平明显升高（P<0.01）,脑脊液中钠离子水平明显升高（P<0.05）。结论:高盐饮食可导致UT-B^-/-小鼠平均动脉压明显升高,其机制与升高小鼠血清AngⅡ和脑脊液钠离子水平有关。更多还原

【Abstract】 Objective:To investigate the effect of high salt diet on the arterial blood pressure in the ureatransporter B（UT-B）gene depletion(UT-B^-/-)mice,and to clarify the possible mechanism of the UT-B^-/-leading to the changes in the arterial blood pressure of the mice.Methods:The heterozygous(UT-B^+/-)mice were mated to obtain the wild-type(UT-B^+/+)and UT-B^-/-mice with the same genetic background.The 4-week-old male UT-B^+/+and UT-B^-/-mice were selected and fed on normal diet（0.3%NaCl）or high salt diet（8.0%NaCl）for 4weeks.The mice were divided into UT-B^+/+mice+normal diet(UT-B^+/++N)group,UT-B^-/-mice+normal diet(UT-B^-/-+N)group,UT-B^+/+mice+high salt diet(UT-B^+/++H)group,and UT-B^-/-mice+high salt diet(UT-B^-/-+H)group.The changes in water intakes and mean arterial pressures of the mice in various groups were monitored;RT-PCR,Western blotting and immunohistochemistry were used to detect the expression levels and location of UT-B mRNA and protein in choroid plexus（CP）of the brain tissue of the mice.The levels of serum angiotensinⅡ（AngⅡ）and the Na⁺levels in cerebrospinal fluid of the mice in various groups were determined by ELISA.Results:The PCR results of genomic DNA of mouse tail showed that there was a400bp base fragment in the UT-B^+/+mice,250and 400bp base fragments in the UT-B^+/-mice,and 250bp base fragment in the UT-B^-/-mice.Compared with normal salt diet group,the water intake of the mice in high salt diet was significantly increased（P<0.01）;compared with UT-B^-/-+N group and UT-B^+/++H group,the mean arterial pressure of the mice in UT-B^-/-+H group was significantly increased（P<0.01）.The UT-B mRNA and protein expressed in the epithelial cells of CP in the UT-B^+/+mice.Compared with UT-B^-/-+N group and UT-B^+/+mice+H group,the AngⅡlevel in serum of the mice in UT-B^-/-mice+H group was significantly increased（P<0.01）;the Na⁺level in cerebrospinal fluid of the mice was significantly increased（P<0.05）.Conclusion:High salt diet can cause a significant increase in the mean arterial pressure in the UT-B^-/-mice,and its mechanism is related to increasing the serum AngⅡlevel and the Na⁺level in cerebrospinal fluid in the mice.更多还原