三甲基氯化锡对亚慢性染毒大鼠肾氢钾ATP酶活力及蛋白与基因表达的研究

目的 探索三甲基氯化锡(trimethyltin chloride,TMT)对亚慢性染毒大鼠肾氢钾ATP酶活力、蛋白和基因表达水平的影响.方法 取6周龄雌性SD大鼠55只,随机分成对照、低剂量、中剂量、高剂量和超高剂量组,共5组,每组11只,分别按0、8.20、32.81、131.25、262.50μg·kg-1·d-1的TMT剂量经饮水亚慢性染毒,14周后测定血钾水平,取大鼠肾脏,用定磷法测量氢钾ATP活力,用免疫印迹法测定肾氢钾ATP酶蛋白表达水平,用实时定量-聚合酶链反应法测定肾氢钾ATP酶的mRNA表达水平.结果 与对照组(6.9±0.3)mmol/L]比较,超高剂量组血钾水平(5.6±0.4)mmol/L]明显降低,差异有统计学意义(P＜.01).低剂量和超高剂量组氢钾ATP酶活力分别为(4.50±1.45)、(435±-0.72)μmolPi·mgprot-1·h-1,明显低于对照组(6.55±0.77)μmolPi·mgprot-1·h-1],差异有统计学意义(P＜0.05).与对照组比较,超高剂量组氢钾ATP酶蛋白和mRNA表达水平差异均无统计学意义(P＞0.05).结论 TMT亚慢性接触可抑制氢钾ATP酶的活力,但不抑制该酶的蛋白和基冈表达.

Abstract：

Objective To study the activity、protein and gene expression of renal HK-ATPase (HKA) in rats subchronicly exposed to trimethyltin chloride (TMT). Methods In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 μg·kg-1 ·d-1 for 14 weeks.Then serum K+ levels were measured; the activities of H K-ATPase (HKA) in kidneys were detected by the method of determinenate phosphorus content;Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. Results The serum K + level in super-high dosage group was (5.6±0.4) mmol/L, which was significantly lower than that (6.9±0.3) mmol/L] in control group (P＜0.01).The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50±1.45 and 4.55±0.72 μmolPi·mg prot-1h-1, respectively, which were significantly lower than that (6.55±0.77 μmol Pi ·mg prot-1h-1) in control group (P＜0.05). Conclusion When rats were exposed subchronicly to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.

Study on activities and protein and gene expression of renal H+-K+-ATPase in rats subchronicly exposed to trimethyltin chloride

Objective To study the activity、protein and gene expression of renal HK-ATPase (HKA) in rats subchronicly exposed to trimethyltin chloride (TMT). Methods In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 μg·kg-1 ·d-1 for 14 weeks.Then serum K+ levels were measured; the activities of H K-ATPase (HKA) in kidneys were detected by the method of determinenate phosphorus content;Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. Results The serum K + level in super-high dosage group was (5.6±0.4) mmol/L, which was significantly lower than that (6.9±0.3) mmol/L] in control group (P＜0.01).The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50±1.45 and 4.55±0.72 μmolPi·mg prot-1h-1, respectively, which were significantly lower than that (6.55±0.77 μmol Pi ·mg prot-1h-1) in control group (P＜0.05). Conclusion When rats were exposed subchronicly to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.