可溶性Tie2融合蛋白对尿毒症腹膜透析大鼠血管新生的影响

目的 观察可溶性Tie2融合蛋白(sTie2/Fc)对尿毒症腹膜透析大鼠腹膜血管新生的影响.方法 48只雄性SD大鼠,按随机数字表法分为以下6组:正常对照组、假手术组、尿毒症非腹透组、4.25％腹透组、sTie2/Fc 2.5 μg/kg干预组、sTie2/Fc 5.0 μg/kg干预组.腹透组按照4.25％腹透液30...     

七氟醚对大鼠肾缺血再灌注损伤的影响及Na+-2Cl--K+协同转运蛋白1和水通道蛋白2在其中的作用

目的 探讨七氟醚对大鼠肾缺血再灌注损伤的影响及Na+-2Cl--K+协同转运蛋白1(BSC1)和水通道蛋白2(AQP2)在其中的作用.方法 健康雄性SD大鼠24只,8～12周龄,体重125 ～145 g,采用随机数字表法,将大鼠随机分为3组(n=8)∶假手术组(S组)、肾缺血再灌注组(I/R组)和七氟醚组(Sev组).采用夹闭肾动脉45 min再灌注24 h的方法制备双侧肾脏缺血再灌注损伤模型.Sev组吸入1 MAC(2.2％)七氟醚,意识消失后开始制备模型,并吸入1 MAC(2.2％)七氟醚3h.于模型制备前24 h(T1)和再灌注24 h(T2)时采集尿样,记录尿量,测定尿比重、肌酐(Cr)水平,计算内生肌酐清除率(Ccr);T2时采集下腔静脉血样,测定血清BUN和Cr、MDA浓度、SOD和髓过氧化物酶(MPO)活性浓度;取血后取左侧肾脏,观察肾组织病理学结果,进行肾小管损伤程度评分,测定肾组织SOD和MPO活性、MDA含量,分别采用免疫组化法和Western blot法测定AQP2和BSC1的表达.结果 与S组比较,I/R组和Sev组T2时尿量增加,血清BUN和Cr浓度升高,尿比重和Ccr降低,血清和肾组织MPO、MDA水平升高,SOD活性降低,肾小管损伤评分升高,肾组织AQP2和BSC1表达水平下调(P＜0.05);与I/R组比较,Sev组Ccr升高,血清BUN和Cr浓度降低,血清和肾组织MPO、MDA水平降低,SOD活性升高,肾小管损伤评分降低,肾组织AQP2和BSC1表达水平上调(P＜0.05),尿量和尿比重差异无统计学意义(P＞0.05),肾组织病理学损伤减轻.结论 七氟醚可减轻大鼠肾缺血再灌注损伤,其机制与上调BSC1和AQP2的表达有关.     

Effects of 1 alpha,25- and 24R,25-dihydroxyvitamin D3 on aluminum-induced rickets in growing uremic rats

Rats were subjected to a two-stage subtotal nephrectomy or sham operation, and treated with aluminum (Al) or both aluminum and vitamin D3 metabolites for 5 weeks with a cumulative dose of 13.6 mg aluminum. Animals were injected with 3H-thymidine and 3H-proline. The following analyses were performed: quantitative histology of tibial metaphyses and cytomorphometric electron microscopy of osteoclasts, quantitative (ICP-spectroscopy) and qualitative determination (histochemical staining) of aluminum within organs, and serum biochemistry (Ca, P, Mg, vitamin D3 metabolites, alkaline phosphatase, urea). The following new facts of the aluminum-related bone disease became evident: (a) Application of aluminum to growing uremic rats induced rickets, whose major epiphyseal growth plate changes were 1 alpha,25(OH)2D3-dependent. Addition of 1 alpha,25(OH)2D3 prevented the formation of rachitic metaphysis, but failed to prevent osteoid accumulation on epiphyseal and metaphyseal trabecular surfaces. Moreover, calcitriol produced hyperosteoidosis and osteosclerosis in the same rats. Aluminum did not alter the function of osteoblasts, while osteoclasts seemed inactivated. (b) The development of rickets was associated with suppressed serum levels of 1,25(OH)2D3, reduced phosphorus level and the high content of aluminum in the bone, kidney, and liver. The addition of 24R,25(OH)2D3 markedly exaggerated the reduction of serum levels of calcitriol. We suggested that aluminum induces rickets in growing uremic rats, which consists of two components: vitamin D refractory osteomalacia and 1 alpha,25(OH)2D3-dependent epiphyseal growth plate changes.     

选择性环氧化酶2抑制剂抑制尿毒症大鼠甲状旁腺异常增生

目的 评价环氧化酶2(COX2)抑制剂塞来昔布(celecoxib)对尿毒症大鼠甲状旁腺(PG)异常增生的影响.方法 通过5/6肾大部分切除结合高磷饮食(P 1.2％,Ca 1.2％)建立尿毒症甲状旁腺功能亢进症(甲旁亢)大鼠模型,存活大鼠按随机数字表法分成尿毒症甲旁亢非用药组(Nx-HP组,n=17)、塞来昔布预防组(Prey组,n=18,建模后1d起给塞来昔布100 mg· kg-1· d-1)和塞来昔布治疗组(Ther组,n=18,建模1个月后给塞来昔布100 mg·kg-1·d-1),并以假手术组作为对照(Sham组,n=14).12周后检测各组大鼠肾功能、血甲状旁腺激素(iPTH)水平、PG大小以及PG中增殖细胞核抗原(PCNA)、COX2表达.结果 Nx-HP组大鼠血清iPTH水平较Sham组显著升高[(100.73±4.35) ng/L比(34.77±0.83) ng/L,P＜0.01],塞来昔布干预后iPTH水平显著下降[Prev组(87.36±2.18) ng/L,Ther组(87.47±1.76) ng/L](均P＜ 0.05).计算显微镜下PG最大面积显示,Nx-HP大鼠PG最大面积显著增大,是Sham组的5.28倍[(2.436±0.372) mm2/kg比(0.461±0.089) mm2/kg,P＜0.01];而Prey组[(0.987±0.254)mm2/kg]和Ther组[(1.270±0.305) mm2/kg]PG分别缩小59.47％(P＜0.01)和47.87％ (P＜0.05),两组间差异无统计学意义.PCNA在Sham组PG中仅少量表达,Nx-HP组显著增多,塞来昔布干预后PCNA阳性细胞明显减少,Prey组和Ther组蛋白表达水平分别降低52.91％和34.68％(均P＜0.05).COX2在Sham组PG中几乎未见表达,但在尿毒症大鼠中明显增多,Nx-HP组、Prey组和Ther组分别为Sham组的2.47倍、2.34倍和3.04倍(均P＜0.05),而3组间差异无统计学意义.实时定量PCR检测PCNA和COX2基因水平显示同样变化趋势.结论 选择性COX2抑制剂塞来昔布可以显著抑制尿毒症大鼠甲旁亢和甲状旁腺增生.     

Effect of vitamin D3, 25-hydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 on parathyroid hormone secretion

Summary The active vitamin D metabolite 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] causes marked suppression of both pre-proparathyroid hormone messenger RNA (pre-proPTH mRNA) and parathyroid hormone (PTH) secretion. These effects are dose dependent and reversible when tested in anin vitro primary tissue culture cell system using normal bovine parathyroid cells. In the current studies, the precursors of 1,25(OH)₂D₃ and the related metabolite 24,25-dihydroxyvitamin D₃ [24,25(OH)₂D₃], were used in the same culture system to test for possible regulatory effects. The results were compared with identically prepared cells exposed to 1,25(OH)₂D₃. In short-term studies (30–120 minutes), none of the vitamin D-related compounds produced any effect on PTH secretion. In long-term studies (24–48 hours, using primary tissue culture in the presence of test agents), neither vitamin D₃ nor 25(OH)D₃ affected PTH secretion or pre-proPTH mRNA over the concentration range 10⁻¹¹–10⁻⁷M. On the other hand, 24,25(OH)₂D₃ produced significant suppression of both pre-proPTH mRNA (77% of control,P<.01) and PTH secretion (75% of control,P<.005) at 10⁻⁷ M. By comparison, 10⁻¹¹ M 1,25(OH)₂D₃ produced levels of suppression (25–30%) of both pre-proPTH mRNA and PTH secretion comparable to 10⁻⁷ M 24,25(OH)₂D₃, while even greater suppression (40–50%) occurred at 10⁻⁹-10⁻⁷ M 1,25(OH)₂D₃. From these studies, we conclude that vitamin D₃ and 25(OH)D₃ do not have significant effects on PTH synthesis and secretion over the range of doses tested. Compared with 1,25(OH)₂D₃, 24,25(OH)₂D₃ exhibits mild suppression at pharmacologic concentrations. The effect of 24,25(OH)₂D₃ prabably occurs through weak interaction of 24,25(OH)₂D₃ with the 1,25(OH)₂D₃ receptor.     

Effect of long-term administration of 1,25-dihydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3 on the calcium content of the aorta, heart and kidney of normal and uremic rats

Studies in uremic rats were performed to see whether or not the long-term administration of therapeutical doses of 1,25-Dihydroxyvitamin D3 or 1 alpha-hydroxyvitamin D3 would induce histological changes in the aorta or increase the calcium content of the aorta or the heart. In contrast to observations of others, no effect of both vitamin D sterols could be observed on both investigated tissues. However, the remnant kidneys of the rats treated with both vitamin D compounds showed a significantly increased calcium content. According to these results one cannot exclude that the chronic application of active vitamin D metabolites has induced a calcium deposition in the remnant kidney. This finding deserves special attention, although we found, on the other hand, no evidence that an underlying arterial disease is aggravated by this therapy.     

活性维生素D3对单侧输尿管结扎小鼠肾组织α平滑肌肌动蛋白和纤连蛋白表达的影响

小管间质纤维化是所有肾脏疾病进行性肾功能衰竭的共同病理改变。目前尚无有效的药物能够阻止和(或)逆转肾间质纤维化。肾间质内肌成纤维母细胞的聚集是小管间质纤维化的特征,且与纤维化的程度和肾功能进行性减退的速度密切相关。研究表明,活性维生素D3 (VitD3)除具备调节钙磷代谢作用之外,还能够保护肾小球上皮细胞和系膜细胞,促进多种细胞分化,抑制细胞增殖等。本研究通过单侧输尿管结扎(UUO)的方法建立小管间质纤维化动物模型,观察VitD3减少间质内肌成纤维母细胞聚集和阻止纤维化的作用。     

维生素D3对大鼠血清铁和肝脏铁调素基因表达的影响

目的探讨维生素D3对大鼠体内铁代谢的影响。方法雌性SD大鼠12只,随机分成2组:实验组和对照组。实验组给予肌肉注射维生素D3 3×105 U/Kg,每周一次,持续4周;对照组按相同方法给予肌肉注射生理盐水。用全自动生化分析仪测大鼠血清钙、铁水平,用一步法逆转录聚合酶链反应方法测定肝脏铁调素(hepcidin)的mRNA水平。结果对照组大鼠血清钙、铁水平分别为2.48±0.03mmol/L和58.06±4.14umol/L;实验组大鼠血清钙、铁水平分别为3.01±0.12mmol/L和51.02±5.31umol/L;与对照组相比,实验组大鼠血清钙显著升高(P<0.01),血清铁显著降低(P<0.05),肝脏铁调素mRNA水平无显著变化。结论维生素D3可能通过增加肠道对钙的吸收降低了血清铁。     

Increase of bone volume in vitamin D-repleted rats by massive administration of 24R,25(OH)2D3

Summary A large dose of 24R,25(OH)₂D₃ was administered to the vitamin D-repleted rat to examine its effect on the bone. Male Wistar rats were fed a diet containing 0, 0.025, 1.25, 4.0, and 12.5 ppm 24R,25(OH)₂D₃ for 2 years starting at age 6 weeks. The estimated amounts of daily intake of 24R,25(OH)₂D₃ were 0, 93, 4640, 14680, and 49580 ng/100 g body weight, respectively. No notable difference was found in either the weight or the death rate of the animal. The long-term administration of massive doses of 24R,25(OH)₂D₃ did not lead to hypercalcemia nor did it affect the blood phosphorus, alkaline-phosphatase, or creatinine levels. Radiographs revealed a striking increase in the bone density on the bones from the animals treated with 1.25 ppm or more 24R,25(OH)₂D₃. Direct single photon absorptiometry revealed a dose-dependent increase in total bone minerals of both the femur and coccyx. Histological examination revealed a marked increase in the cortical thickness of the femur as well as in the cancellous bone volume of the coccyx. Polarizing microscopy demonstrated the lamellar structure of the bone, and undecalcified sections confirmed the increase of mineralized bone. Ash weight, calcium, phosphorus, and magnesium contents on the tibia and fibula also indicated the ascending dose-dependent increase up to 150% of the control. The parameters of bone size were not altered in any group. These results clearly suggest that 24R,25(OH)₂D₃ given in massive doses has the pharmacological action of increasing bone volume in the rat without causing remarkable hypercalcemia.     

Effects of 1α, 25-dihydroxyvitamin D3 on memory CD4+ T cells of focal proliferative IgA nephropathy

Objective To explore the effects of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] on memory CD4+ T cells of focal proliferative IgA nephropathy (IgAN）patients. Methods (1) Total of twenty incipient focal proliferative IgAN patients (Lee classification: Ⅲ level) were chosen as IgAN group and 20 healthy volunteers were chosen as healthy control group. The level of serum 1,25(OH)2D3 was measured by radioimmunoassay (RIA). Peripheral blood mononuclear cells (PBMCs) were separated by the method of Ficoll density gradient centrifugation and were stimulated with anti-CD3/anti-CD28 in the absence or presence of various concentrations of 1,25(OH)2D3, Dexamethasone(DEX) and 1,25(OH)2D3 and DEX combined. PBMCs were cultured for 72 hours and the levels of IFN-γ, IL-4, IL-17A, Foxp3 were measured by flow cytometry(FCM), standing for the levels of Th1, Th2, Th17, Treg. (2) IgAN group was divided into two subgroups (proteinuria＜1 g/24 h subgroup, proteinuria≥1 g/24 h subgroup), then the serum levels of 1,25(OH)2D3, IFN-γ, IL-4, IL-17A, Foxp3 were compared. Results Compared with healthy control group, serum 1,25(OH)2D3 level of IgAN group was significantly lower (P＜0.05). Serum 1,25(OH)2D3 level in proteinuria≥1 g/24 h subgroup was significantly lower than proteinuria＜1 g/24 h subgroup and healthy control group (P＜0.05). The level in proteinuria＜1 g/24 h subgroup was lower than healthy control group, but the difference was not statistically significant (P＞0.05). (2) The levels of IFN-γ and IL-17A and the ratios of IFN-γ/IL-4, IL-17A/Foxp3 in IgAN group increased significantly compared with healthy control group (all P＜0.05), and the level of Foxp3 decreased significantly (P＜0.05). The level of IL-4 also increased, but the difference was not statistically significant (P＞0.05). The levels of IFN-γ and IL-17A and the ratio of IL-17A/Foxp3 in proteinuria≥1 g/24 h subgroup increased significantly, and the level of Foxp3 decreased significantly, compared with urinary protein＜1 g/24 h subgroup and healthy control group (P＜0.05). The ratio of IFN-γ/IL-4 in proteinuria≥1 g/24 h subgroup and proteinuria＜1 g/24 h subgroup all increased, compared with healthy control group, and the ratio in proteinuria≥1 g/24 h subgroup increased significantly (P＜0.05). There was no significant difference in the level of IL-4 among all groups. (3) After treatment with 1,25(OH)2D3, the levels of IFN-γ and IL-17A and the ratios of IFN-γ/IL-4 and IL-17A/Foxp3 decreased significantly, and the level of Foxp3 increased significantly (P＜0.05), and these effects were more obvious as the increase of the drug concentration. The level of IL-4 did not change significantly. The combination of 1,25(OH)2D3 and DEX had a synergistic inhibition on the production of IFN-γ, IL-4, IL-17A, and the ratios of IFN-γ/IL-4 and IL-17A/Foxp3, and had a synergistic promotion on the production of Foxp3. Conclusions There is a certain extent of vitamin D deficiency in focal proliferative IgAN patients, which may be associated with the severity of proteinuria. The disorder of immunomodulatory effects of memory CD4+ T cell might exist in the patients of focal proliferative IgAN. 1α,25-dihydroxyvitamin D3 might have beneficial effects on the immunoregulation of memory CD4+T cells of focal proliferative IgAN patients.     

小剂量维生素D受体激活剂(骨化三醇)对血液透析患者血钙及血磷和成纤维细胞生长因子23的影响

目的 探讨小剂量维生素D受体激活剂(骨化三醇)对血液透析患者血钙、血磷和成纤维细胞生长因子23的影响.方法 20例血液透析患者应用骨化三醇(每天0.25μg)治疗,分别于用药前、用药4、8周观察患者血钙、血磷、碱性磷酸酶、全段甲状旁腺激素和成纤维细胞因子23水平.结果 用药4周和8周后患者血钙明显上升(但尚未超过正常范围),与治疗前比较差异有统计学意义(P＜0.01);用药4周和8周后血磷有所下降,但与治疗前比较差异无统计学意义(P＞0.05);用药4周和8周后血碱性磷酸酶明显下降,与治疗前比较差异有统计学意义(P＜0.01);用药4周后血全段甲状旁腺激素有所下降,但与治疗前比较差异无统计学意义(P＞0.05);用药4周和8周后血成纤维细胞因子23明显升高,与治疗前比较差异有统计学意义(P＜0.01).结论 小剂量维生素D受体激活剂(骨化三醇)对维持性血液透析患者具有升高血钙、抑制碱性磷酸酶并升高成纤维细胞生长因子23的作用.     

Effect of rosiglitazone on the expression of AQP-1, VEGF-A and COX-2 in uremic rat of peritoneal dialysis

Objective To investigate the effect of rosiglitazone(RGZ) on peritoneal morphology, function and the expressions of Aquaporin 1 (AQP-1), vascular endothelial growth factor A(VEGF-A) and cyclooxygenase 2(COX-2) in uremic rat of peritoneal dialysis. Methods Thirty Sprague-Dawley rats were randomly divided into five groups. Group S (n=6) was subjected to sham operation. Group N (n=6) was subjected to nephrectomy with silicon catheter inserted, but no peritoneal exposure. Group P (n=6) was subjected to nephrectomy with silicon catheter inserted and receiving daily peritoneal injection through the catheter, using 4.25% peritoneal dialysis fluid 10 ml twice a day for 2 weeks. Group R (n=6) was subjected to nephrectomy with silicon catheter inserted and receiving daily peritoneal injection through the catheter, using 4.25% peritoneal dialysis fluid containing rosiglitazone (0.2 mg/kg) 10 ml twice a day for 2 weeks. Group GW (n=6) was subjected to nephrectomy with silicon catheter inserted and receiving daily peritoneal injection through the catheter, using 4.25% peritoneal dialysis fluid containing rosiglitazone (0.2 mg/kg) and GW9662 (0.2 mg/kg) 10 ml twice a day for 2 weeks. After two weeks of dialysis, a 90 min peritoneal equilibration test was performed and the amount of ultrafiltration was accurately measured. The partial peritoneum tissues of rats were harvested and stained by hematoxylin-eosin (HE), then morphology changes of partial peritoneum were examined by light microscopy. The expression of AQP-1,VEGF-A and COX-2 in omentum were detected with immunohistochemistry assay. AQP-1, VEGF-A and COX-2 mRNA were detected by qRT-PCR. Results Morphology changes of partial peritoneum showed that compared with Group S,a dramatic increase in thickness of the mesothelium-to-muscle layer of peritoneum in Group N, P, R and GW(P＜0.05). Compared with group P, the thickness significantly decreased in Group R(P＜0.05). PET results showed that compared with Group S, ultrafiltration (UF) significantly reduced in Group P, R, and GW(P＜0.05). Compared with Group P, ultrafiltration significantly increased in Group P, R, and GW (P＜0.05). Compared with group S, the expressions of AQP1, VEGF-A and COX-2 mRNA and protein were significantly increased in group P, R and GW(P＜0.05). Compared with group P, the expressions of AQP1, VEGF-A mRNA and protein were significantly decreased in Group R and GW(P＜0.05). Compared with group P, the expressions of COX-2 mRNA and protein were significantly decreased in group R (P＜0.05), while no differences in the expression of COX-2 mRNA and protein in group GW (P＜0.05). Conclusions Rosiglitazone can inhibit peritoneal interstitial and vascular proliferation, protect peritoneal function and increase ultrafiltration. Rosiglitazone can protect peritoneal function probably by inhibiting expression of VEGF-A and COX-2.     

硝苯地平和罗钙全对尿毒症患者甲状旁腺素受体基因表达的影响

目的 观察钙通道阻滞剂硝苯地平和活性维生素Ｄ制剂罗钙全对尿毒症患者外周血单个核细胞（ＰＢＭＣ）上甲状旁腺素（ＰＴＨ）受体基因表达的影响。方法 ３０例非糖尿病常规血液透析患者随机分成硝苯地平组、罗钙全组和安慰剂组,治疗８周。应用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）方法检测用药前后ＰＢＭＣ上ＰＴＨ受体ｍＲＮＡ表达。结果 硝苯地平治疗能使尿毒症患者ＰＢＭＣ上ＰＴＨ受体ｍＲＮＡ的低表达显著上调（０．１４３     

1α，25双羟维生素D3对成骨样细胞增殖与分化的影响

采用同位素掺入，细胞周期、细胞化学和扫描电镜等方法观察了１α，２５双羟维生素Ｄ３［１，２５（ＯＨ）２Ｄ３］对人及大鼠成骨样细胞ＯＳ－７３２和ＲＯＳ１７／２．８增殖及分化的影响。结果表明：１，２５（ＯＨ）２Ｄ３对ＯＳ－７３２细胞增殖的抑制作用呈明显的时效和量效关系。在给１０－７ｍｏｌ／Ｌ的１，２５（ＯＨ）２Ｄ３后第４和第６天，对ＯＳ－７３２细胞生长的抑制率分别为４０％和６０％；对ＤＮＡ，ＲＮＡ和蛋白质合成的抑制作用分别为５９％，４１％和２２％。流式细胞计测定结果表明：１，２５（ＯＨ）２Ｄ３使ＤＮＡ合成受阻；扫描电镜显示：１，２５（ＯＨ）２Ｄ３有抑制ＲＯＳ１７／２．８细胞表面微绒毛的作用。此外，细胞化学染色表明：该激素有增加成骨样细胞碱性磷酸酶活性和促进骨形态形成蛋白合成的作用，即刺激骨形成的作用。     

The effect of irbesartan on the expression of angiopoietin-like protein 2 in the kidneys of type2 diabetes rats

Objective To observe the effect of irbesartan on the expression of angiopoietin-like protein 2 (ANGPTL2) in the diabetic rats kidney and explore the underlying mechanism. Methods A total of sixty male SD rats were divided into normal control group (NC group, n=15) and experimental group (n=45) randomly. The experimental group was fed with high sugar-fat diet and given a low dose streptozocin（STZ 30 mg/kg）to establish type 2 diabetic model. Rats successfully induced diabetes were randomly divided into 2 groups: diabetes group (DM) and irbesartan group (DI). Weight, blood pressure, blood glucose, serum creatinine (Scr), blood urea nitrogen(BUN), 24 hour urinary albumin(UAL) and renal histomorphology were observed after drug intervention at the 4th, 8th and 12th weeks. The expression of ANGPTL2 in renal tissue were detected by immunohistochemistry, real-time PCR and Western blotting. Results The levels of Scr, BUN, TG, TC and UAL in group DM were higher than in group NC at the 4th, 8th and 12th week (all P＜0.05).Compared with that in group DM, above indexes were lower in group DI at the 4th, 8th and 12th week (all P＜0.05). The pathological changes of the kidney in group DM were more serious than that in group DI. The expression of ANGPTL2 in group DM was much higher than that in group NC at the 4th, 8th and 12th week (all P＜0.05), and irbesartan treatment inhibited the up-regulation of ANGPTL2 in group DI(all P＜0.05). Conclusion The expression of ANGPTL2 increases in T2DM rats kidney tissue with time and irbesartan can inhibit the up-regulation of ANGPTL2 in T2DM rats.     

Effect of 1 alpha, 25(OH)2D3 on experimental rat nephrotoxic serum nephritis

We studied immunoregulatory effects of 1 alpha, 25(OH)2D3 in vivo using experimental rat nephrotoxic serum nephritis (NTSN). Experimental rats were divided into 3 groups according to the doses of 1 alpha (OH)D3, i.e. the control group (untreated group), the D30.02 group (0.02 microgram/Kg/day), and D30.5 group (0.5 microgram/Kg/day). The present study demonstrated that rats with NTSN receiving 0.5 microgram/Kg/day of 1 alpha (OH)D3 showed much lower urinary protein excretion as well as lesser histopathological changes in both heterologous and autologous phase as compared with rats without such treatments. On the other hand, the results in the D30.02 group varied. And also, the following were demonstrated in the D30.5 group as compared with the control group: 1) CH50 levels were maintained almost normally, 2) the staining of rat C3 was clearly lesser, 3) the number of intraglomerular OX41 and W3/13 labelled cells was significantly lower, 4) the response of cultured spleen lymphocytes stimulated with ConA and LPS was clearly inhibited, 5) the helper T cell/suppressor T cell ratio was lower, and 6) the staining of rat IgG was lesser. Therefore, it was speculated that the inhibitory effects of 1 alpha, 25(OH)2D3 on complement activation might play important roles. And also, we postulated that the following mechanisms were involved: 1) the inhibition of antibody generation due to the blocking of T lymphocyte proliferation and functions and; 2) the inhibition of intraglomerular macrophage infiltration caused by blocking of T lymphocyte functions. In conclusion, our study indicated that 1 alpha, 25(OH)2D3 had a new facet of immunoregulatory function in experimental rat NTSN.     

Effect of the JAK2/STAT3 signaling pathway on epithelial mesenchymal transition of the peritoneum in uremic peritoneal dialysis rats

Objective To investigate whether the JAK2/STAT3 signaling pathway is involved in the epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells in uremic peritoneal dialysis (PD) rats. Methods A total of 48 male Sprague-Dawley (SD) rats were randomly separated into six groups: normal control group (NC group, n=8), sham group (n=8), uremic group (n=8), PD group (n=8), S3I-201 control group (n=8) and S3I-201 group (n=8). Uremic model generated by 5/6 nephrectomy surgery in rats was established. The rats of PD group, S3I-201 control group and S3I-201 group received daily infusion of 4.25% glucose-based peritoneal dialysate fluid (3 ml/100 g) from PD catheters for 28 days. Rats of S3I-201 group were injected with STAT3 inhibitor S3I-201 (2.5 mg/kg) solution from the catheters every other day; the same dose of the solvent of S3I-201 was simultaneously given to S3I-201 control group rats. After PD for 28 days, peritoneal function, pathologic changes, and microvessel density (MVD) were evaluated. Creatinine, urea nitrogen and interleukin-6 (IL-6) concentration in blood and dialysate, and protein and mRNA levels of phospho-JAK2 (p-JAK2), phospho-STAT3 (p-STAT3), E-cadherin, alpha-smooth muscle actin (α-SMA) and vascular endothelial growth factor (VEGF) in peritoneum were determined. Results Uremia and peritoneal dialysate could aggravate the peritoneal function and elevate peritoneal thickness and MVD. They could also increased the concentration of IL-6 in blood and dialysate and the expression levels of α-SMA, VEGF, p-JAK2 and p-STAT3 in peritoneum, while lowering E-cadherin expression in peritoneum. These manifestations were even more remarkable in PD group compared to those in uremic group. There was no statistical difference between the S3I-201 control group and the PD group as regards all the index (all P＞0.05). Compared with the S3I-201 control group, the rats treated with S3I-201 showed better peritoneal function. S3I-201 could reduce peritoneal thickness (P＜0.05), MVD (P＜0.05), the concentration of IL-6 in blood and dialysate, the mRNA and protein expression of α-SMA, VEGF, p-JAK2 and p-STAT3 (all P＜0.05), while enhance the mRNA and protein expression of E-cadherin (all P＜0.05). Conclusions After STAT3 is inhibited, the peritoneal thickness, MVD and IL-6 concentration in PD rats are decreased, and EMT is also inhibited, while peritoneal function is improved. The JAK2/STAT3 signaling pathway may thus be involved in the process of EMT of peritoneum in uremic peritoneal dialysis rats by regulating the expression of IL-6.