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Objective To investigate the effect of hyperoxia on fluid transport by fetal distal lung epithelia(FDLE) and the expression of epithelial sodium channel(ENaC) in these cells.Methods FDLE were isolated and randomized into hyperoxia group and normoxia group,which were primarily cultured under hyperoxic or normoxic conditions,respectively.Fluid transport was measured using monolayers of FDLE cultured on Transwell permeable inserts.Western blot was applied to examine the α-ENaC expression.Results Fluid transport across monolayer of FDLE was increased in cells exposed to hyperoxia compaired with cells cultured in normoxic conditions (1.78 ± 0.19 vs 1.06 ± 0.11,P ＜ 0.001).Amiloride significantly decreased the fluid transport in both of the hyperoxia and normoxia groups,but in the presence of amiloride there were no difference between the two groups.The expression of α-ENaC was inhibited by hyperoxia to some extent(24h:0.44 ±0.04 vs 0.40 ±0.04,P=0.22; 48h:0.35 ±0.03 vs 0.47 ±0.06,P =0.03).Conclusion Hyperoxia enhanced total and amiloride-sensitive fluid transport by FDLE.However,the expression of α-ENaC decreased in these cells.
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Objective To investigate the changes of epithelial sodium channel(ENaC) expression and sodium and water transport function in the neonatal rat pulmonary edema induced by hyperoxia.Methods The neonatal rats were randomly divided into the hyperoxia group and the control group.After 1,3,5 and 7 d hyperoxia exposure,the lung tissues were collected to measure the wet-to-dry weight ratio and the expression of α-,β-and γ-ENaC subunits were detected by western blot analysis.Alveolar fluid clearance (AFC) and amiloride-sensitive AFC were measured after 5 d to reveal the effect of hyperoxia on the activity of ENaC.Results The lung water contents significantly increased in the hyperoxia group indicating that pulmonary edemahappened(3 d:(6.37 ±0.64) vs (5.56±0.15),t=3.46,P＜0.01;5 d:(5.86 +0.52) vs (5.11±0.21),t=-3.82,P ＜0.01;7 d:(5.56±0.45) vs (4.80±0.09),t =-4.72,P ＜0.01).AFC increased significantly,but no significant difference was found in amiloride-insensitive AFC between the two groups which indicate that amiloride-sensitive AFC increased significantly (AFC:(20.32 ± 3.33) ％ vs (12.97 ± 2.46) ％,t =-6.16,P ＜ 0.01 ; amiloride-insensitive AFC:(10.42 ± 3.44) ％ vs (8.67 ± 3.13) ％,t =-1.30 P =0.21).The expression of α-,β-and γ-ENaC did not reduced after hyperoxia exposure compared with the control group.Conclusion Although bronchopulmonary dysplasia of early pulmonary edema induced by hyperoxia,dysfunctional transport of Na + may not be a key factor involved in pulmonary edema at the early stage of bronchopulmonary dysplasia.
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Objective To investigate the effect of hyperoxia on the expression and transport function of epithelial sodium channel (ENaC) in neonatal rat alveolar epithelial type Ⅱ(AT Ⅱ) cells.Methods AT Ⅱ cells were isolated from neonatal rats,and primarily cultured under hyperoxic or normoxic conditions.Western blot was applied to examine the ENaC expression,and the amiloride-sensitive Na + currents were recorded using the whole-cell patch clamp technique.Results Hyperoxia upregulate the expression of β-ENaC and γ-ENaC subunits in the neonatal rat ATⅡ cells(β-ENaC:1 d:0.43 ±0.06 vs0.32 ±0.04,P =0.047;2 d:0.73±0.06 vs 0.50±0.08,P =0.019;3 d:0.72 ±0.08 vs 0.52 ±0.06,P =0.027;γ-ENaC:1 d:0.64±0.05 vs0.53 ±0.05,P =0.044;2 d:0.76 ±0.03 vs 0.52 ±0.04,P =0.001 ;3 d:0.77 ±0.06 vs 0.61 ±0.05,P =0.025).In addition,the amiloride-sensitive Na+ currents in hyperoxia-exposed AT Ⅱ cells were also increased (1d:13.71 ±2.77 vs8.92±1.38,P＜0.001;2d:29.12±11.03 vs 10.41 ±1.80,P＜0.001),which was consistent with the upregulated expression of β-ENaC and γ-ENaC.However,the expression of α-ENaC was inhibited by hyperoxia to some extent (1 d:0.31 ± 0.05 vs 0.46 ± 0.05,P =0.025 ; 2 d:0.30 ±0.01 vs0.38±0.02,P=0.002;3d:0.37±0.06 vs 0.37 ± 0.08,P =0.983).Conclusion Hyperoxia enhanced the transport function of ENaC in neonatal rat AT Ⅱ cells.Dysfunctional transport of Na + may not be a key factor involving in pulmonary edema at the early stage of bronchopulmonary dysplasia.
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@# ObjectiveTo compare the characteristics of urinary function in the patients with spinal cord injury or stroke. MethodsThe urinary diaries of 40 patients with spinal cord injury and 43 patients with stroke during a week were analyzed. ResultsIn the group of spinal cord injury, the average frequency of incontinence was 11 times a day, the average incontinence volume was (180.6±21.4) ml, and the average residual urine volume was (257±86.5) ml, while in the group of stroke, it was 16 times a day（P>0.05）, (298.8±34.6) ml （P<0.01）, and (28.5±18.5) ml （P<0.01）, respectively. Ultrasonic inspection discovered that 12% patients appeared ureterectasia and hydronephrosis in group of spinal cord injury, but none in group of stroke. ConclusionThere is significant difference of urinary dysfunction between patients with spinal cord injury and stroke, which need different management to protect their upper urinary tract.