为研究温氏土鸡和白洛克鸡胚小肠寡肽转运载体PepT1(Solute carrier family 15 member 1)以及Na+/H+交换载体NHE2(Solute carrier family 9 member 2)和NHE3(Solute carrier family 9 member 3)mRNA的表达规律,选取产蛋日龄相近的温氏...为研究温氏土鸡和白洛克鸡胚小肠寡肽转运载体PepT1(Solute carrier family 15 member 1)以及Na+/H+交换载体NHE2(Solute carrier family 9 member 2)和NHE3(Solute carrier family 9 member 3)mRNA的表达规律,选取产蛋日龄相近的温氏土鸡和白洛克鸡所产种蛋各96枚,每个品种随机分为6组,每组16枚,在相同的条件下进行孵化。分别在9,12,14,17,19胚龄(E)和出壳当天(DOH),每个品种选取16枚鸡胚,采集小肠样品,采用Real-time RT-PCR方法检测小肠PepT1、NHE2和NHE3 mRNA的相对表达丰度。结果显示:从发育性变化来看,PepT1、NHE2和NHE3mRNA在温氏土鸡和白洛克鸡胚小肠的表达丰度都表现为随着胚龄的增加而上调,19胚龄后上调幅度较大;双因素方差分析表明,PepT1、NHE2和NHE3 mRNA的表达丰度在2个品种间无显著差异,但受发育阶段影响,PepT1 mRNA的表达丰度存在"品种×胚龄"的互作效应(P<0.000 1),NHE2和NHE3 mRNA表达丰度无"品种×胚龄"的互作效应(P>0.05)。说明PepT1、NHE2和NHE3 mRNA表达丰度在温氏土鸡和白洛克鸡胚小肠中具有相同的发育模式,其表达量受发育水平的影响,但品种间差异不显著。展开更多
Thiazolidinediones(TZDs), pharmacological activators of peroxisome-proliferator-activated receptors γ(PPARγ), significantly improve insulin resistance and lower plasma glucose concentrations. However, the use of TZD...Thiazolidinediones(TZDs), pharmacological activators of peroxisome-proliferator-activated receptors γ(PPARγ), significantly improve insulin resistance and lower plasma glucose concentrations. However, the use of TZDs is associated with plasma volume expansion, the mechanism of which has been a matter of controversy. Originally, PPARγ-mediated enhanced transcription of the epithelial Na channel(ENaC) γ subunit was thought to play a central role in TZD-induced volume expansion. However, later studies suggested that the activation of ENaC alone could not explain TZD-induced volume expansion. We have recently shown that TZDs rapidly stimulate sodium-coupled bicarbonate absorption from renal proximal tubule(PT) in vitro and in vivo. TZD-induced transport stimulation was dependent on PPARγ/Src/EGFR/ERK, and observed in rat, rabbit and human. However, this stimulation was not observed in mouse PTs where Src/EGFR is constitutively activated. Analysis in mouse embryonic fibroblast cells confirmed the existence of PPARγ/Src-dependent non-genomic signaling, which requires the ligand binding ability but not the transcriptional activity of PPARγ. The TZD-induced enhancement of association between PPARγ and Src supports an obligatory role for Src in this signaling. These results support the view that TZD-induced volume expansion is multifactorial. In addition to the PPARγ-dependent enhanced expression of the sodium transport system(s) in distal nephrons, the PPARγ-dependent non-genomic stimulation of renal proximal transport may be also involved in TZD-induced volume expansion.展开更多
文摘为研究温氏土鸡和白洛克鸡胚小肠寡肽转运载体PepT1(Solute carrier family 15 member 1)以及Na+/H+交换载体NHE2(Solute carrier family 9 member 2)和NHE3(Solute carrier family 9 member 3)mRNA的表达规律,选取产蛋日龄相近的温氏土鸡和白洛克鸡所产种蛋各96枚,每个品种随机分为6组,每组16枚,在相同的条件下进行孵化。分别在9,12,14,17,19胚龄(E)和出壳当天(DOH),每个品种选取16枚鸡胚,采集小肠样品,采用Real-time RT-PCR方法检测小肠PepT1、NHE2和NHE3 mRNA的相对表达丰度。结果显示:从发育性变化来看,PepT1、NHE2和NHE3mRNA在温氏土鸡和白洛克鸡胚小肠的表达丰度都表现为随着胚龄的增加而上调,19胚龄后上调幅度较大;双因素方差分析表明,PepT1、NHE2和NHE3 mRNA的表达丰度在2个品种间无显著差异,但受发育阶段影响,PepT1 mRNA的表达丰度存在"品种×胚龄"的互作效应(P<0.000 1),NHE2和NHE3 mRNA表达丰度无"品种×胚龄"的互作效应(P>0.05)。说明PepT1、NHE2和NHE3 mRNA表达丰度在温氏土鸡和白洛克鸡胚小肠中具有相同的发育模式,其表达量受发育水平的影响,但品种间差异不显著。
文摘Thiazolidinediones(TZDs), pharmacological activators of peroxisome-proliferator-activated receptors γ(PPARγ), significantly improve insulin resistance and lower plasma glucose concentrations. However, the use of TZDs is associated with plasma volume expansion, the mechanism of which has been a matter of controversy. Originally, PPARγ-mediated enhanced transcription of the epithelial Na channel(ENaC) γ subunit was thought to play a central role in TZD-induced volume expansion. However, later studies suggested that the activation of ENaC alone could not explain TZD-induced volume expansion. We have recently shown that TZDs rapidly stimulate sodium-coupled bicarbonate absorption from renal proximal tubule(PT) in vitro and in vivo. TZD-induced transport stimulation was dependent on PPARγ/Src/EGFR/ERK, and observed in rat, rabbit and human. However, this stimulation was not observed in mouse PTs where Src/EGFR is constitutively activated. Analysis in mouse embryonic fibroblast cells confirmed the existence of PPARγ/Src-dependent non-genomic signaling, which requires the ligand binding ability but not the transcriptional activity of PPARγ. The TZD-induced enhancement of association between PPARγ and Src supports an obligatory role for Src in this signaling. These results support the view that TZD-induced volume expansion is multifactorial. In addition to the PPARγ-dependent enhanced expression of the sodium transport system(s) in distal nephrons, the PPARγ-dependent non-genomic stimulation of renal proximal transport may be also involved in TZD-induced volume expansion.
