Effect of high salt diet on arterial blood pressure in urea transporter B gene depletion mice and its mechanism / 吉林大学学报(医学版)

ABSTRACT

Objective: To investigate the effect of high salt diet on the arterial blood pressure in the urea transporter 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-B1/) and UT-B-/- mice with the same genetic background. The 4-week-old male UT-B1/1 and UT-B-/- mice were selected and fed on normal diet (0. 3% NaCl) or high salt diet (8. 0% NaCl) for 4 weeks. The mice were divided into UT-B/1 mice + normal diet (UT-B /1 +N) group, UT-B-/- mice + normal diet (UT-B-/- +N) group, UT-B1/1 mice+high salt diet (UT-B /1 +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 angiotensin II (Ang II) 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 a 400 bp base fragment in the UT-B mice, 250 and 400 bp base fragments in the UT-B mice, and 250 bp 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-B1/1 + 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/1 mice. Compared with UT-B-/- +N group and UTS1/ mice+H group, the Ang II level 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 Ang II level and the Na' level in cerebrospinal fluid in the mice.