Tetramethylpyrazine stimulates cystic fibrosis transmembrane conductance regulator-mediated anion secretion in distal colon of rodents

AIM: To investigate the effect of tetramethylpyrazine (TMP), an active compound from Ligustiun Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS: The short-circuit current (ISC) technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis (RIA) and a special mouse model of cystic fibrosis.RESULTS: TMP stimulated a concentration-dependent rise in ISC, which was dependent on both Cl- and HCO3-, and inhibited by apical application of diphenylamine-2,2'-dicarboxylic acid (DPC) and glibenclamide, but resistant to 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS). Removal of Na+ from basolateral solution almost completely abolished the ISC response to TMP, but it was insensitive to apical Na+ replacement or apical Na+channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2+chelator, did not significantly alter the TMP-induced ISC. No additive effect of forskolin and 3-isobutyl-1-methylxanthine (IBMX) was observed on the TMP-induced ISc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP (1 mmol/L) elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin (10 μmol/L). The TMP-elicited ISC as well as forskolin- or IBMX-induced ISC were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) presenting defective CFTR functions and secretions.CONCLUSION: TMP may stimulate cAMP-dependent and CFTR-mediated Cl- and HCO3- secretion. This may have implications in the future development of alternative treatment for constipation.

Interaction between enteric epithelial cells and Peyer's patch lymphocytes in response to Shigella lipopolysaccharide: Effect on nitric oxide and IL-6 release

瞄准：在氮的氧化物的版本上调查在伤寒上皮细胞和 Peyer 的补丁的淋巴细胞之间的相互作用的效果(没有) 并且响应志贺氏菌属脂肪的多糖(LPS ) 的 IL-6。方法：人的结肠的上皮细胞(Caco-2 ) 是有 Peyer 的补丁从的淋巴细胞的混合 cocultured 野类型(C57 老鼠) 并且可诱导没有 synthase 大美人老鼠，并且与志贺氏菌属 F2a-12 LPS 质问了。版本没有并且 mIL-6 被 Griess 比色测定和连接酶的免疫吸着剂试金(ELISA ) 分别地测量。结果：当 LPS 挑战不在时，不在 Caco-2 上皮细胞的培养基然而并非在 Peyer 的补丁的淋巴细胞被检测，并且 NO 版本在有从也的淋巴细胞的两 cocultures 是进一步起来调整的野类型或 i NOS 大美人老鼠，与一显著地，高水平与 i NOS 猛烈淋巴细胞在 coculture 观察了。在为 24-h 的志贺氏菌属 F2a-12 LPS 挑战以后，没有生产显著地从野类型的老鼠然而并非从 i NOS 猛烈老鼠与 Peyer 的补丁的淋巴细胞在独自一个的 Caco-2 和 coculture 被增加。LPS 被发现从淋巴细胞刺激 mIL-6 的版本，它被 coculture 与 Caco-2 上皮细胞压制。在从 i NOS 猛烈老鼠的淋巴细胞的导致 LPS 的 mIL-6 生产从野类型的老鼠比那显著地大。结论：Peyer 的补丁的淋巴细胞从伤寒维持没有生产的组成的基础水平上皮的房间 Caco-2。从 Peyer 的补丁的淋巴细胞的导致 LPS 的 mIL-6 版本被 cocultured 上皮细胞压制。当没有变化在在淋巴细胞从的没有生产是可检测的时野类型并且在 LPS 前后的 i NOS 猛烈老鼠质问，不从淋巴细胞看起来起一个禁止的作用在上皮响应 LPS 的没有版本和他们的自己的 mIL-6 版本。