INTESTINAL PERFUSION AND PERMEABILITY IN SEPSIS

描述：（改编自申请人的摘要）这一竞争 更新申请是基于这样的假设，即肠上皮细胞 屏障功能被细胞酸中毒破坏。 在当前 资助的研究，研究人员已经表明，回肠粘膜酸中毒， 在猪体内增加粘膜渗透性， 粘膜细胞（CaCo-2BBe）单层对酸的反应也诱导了 体外上皮通透性。 研究人员的研究还表明， 表明酸中毒促进脂质过氧化，增加细胞内 Fe ~（2+），并部分消耗CaCo-2BBe肠细胞中的细胞ATP。 这些研究还表明，抑制钙蛋白酶和 磷脂酶可改善酸诱导的粘膜通透性增高。 这些研究共同支持细胞内 钙相关紊乱可能是重要的发病机制酸 引起粘膜屏障功能障碍。 本提案将扩大 CaCo-2BBe细胞和单核细胞的研究：1）测量 细胞内[H+]，2）评估酸中毒和ATP的影响 消耗上皮细胞对水溶性大分子的渗透性， 以及颗粒物质如LPS和大肠杆菌。 在 此外，该提案将侧重于细胞骨架的完整性及其 与酸中毒诱导的粘膜细胞通透性功能障碍的关系 在CaCo-2BBe单分子膜中。 研究还将评估 肠细胞中[Ca 2 +]i的酸中毒或中度ATP耗竭，以及 A23187、BAPTA和各种磷脂酶修饰剂的作用 钙蛋白酶和蛋白激酶C对酸性和/或低ATP水平诱导的粘膜炎症反应的影响 通透性功能障碍 所有上述研究都将 CaCo-2BBe细胞系的体外培养。 最后，实验将 确定回肠粘膜通透性的各种决定因素 在大鼠出血性损伤模型的体内研究中， 这些研究将采用体内方法来确定 LPS的移位和大分子穿过回肠的渗透性 上皮

DESCRIPTION: (Adapted from the applicant's abstract) This competing renewal application is based on the hypothesis that gut epithelial barrier function is deranged by cellular acidosis. In the currently funded research, the investigator has shown that ileal mucosal acidosis in pigs increases mucosal permeability in vivo, and that exposure of mucosal cell (CaCo-2BBe) monolayers to acid also induce an increase in epithelial permeability in vitro. The investigator's studies have also shown that acidosis promotes lipid peroxidation, increases intracellular Fe2+, and partly depletes cellular ATP in the CaCo-2BBe enterocytes. These studies have demonstrated also that inhibition of calpain and phospholipases ameliorated acid induced mucosal hyperpermeability. These studies collectively support the concept that intracellular calcium related derangements may be important in the pathogenesis of acid induced mucosal barrier dysfunction. The present proposal will extend the studies of CaCo-2BBe cells and monocytes by: 1) measuring intracellular [H+], 2) assessing the effect of acidosis and ATP depletion on epithelial permeability to water soluble macromolecule as well as to particulate matter such as LPS and E.coli bacteria. In addition the proposal will focus on cytoskeletal integrity and its relationship to acidosis induced mucosal cell permeability dysfunction in CaCo-2BBe monolayers. Studies will evaluate also the effect of acidosis or moderate ATP depletion in the enterocytes on [Ca2+]i, and the effects of A23187, BAPTA, and various modifiers of phospholipases calpains and PKC on the acid and/or low ATP level induced mucosal permeability dysfunction. all of the aforementioned studies are to be carrier in the CaCo-2BBe cell line in vitro. Finally, experiments will ascertain the various determinants of ileal mucosal permeability dysfunction in the in vivo studies in a rat model of hemorrhagic injury. These studies will employ in vivo methodology to determine both translocation of LPS and permeability of macromolecules across the ileal epithelium.