AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： Th...AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium 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： IMP stimulated a conoentration-dependent rise in ISCl, 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 Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） 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 （10μmol/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.展开更多
In this study, we combined silver nanowires with cupro fabrics using a dipping- drying method to prepare electrically conductive fabrics. The silver nanowires were first adhered to and then absorbed by microfibers to ...In this study, we combined silver nanowires with cupro fabrics using a dipping- drying method to prepare electrically conductive fabrics. The silver nanowires were first adhered to and then absorbed by microfibers to form electrically conductive fibers. They also filled the gaps and spaces between the microfibers, and were stacked or piled together to form networks with high electrical conductivity. The electrically conductive fabric had low resistance and good stretchability, e.g., 0.0047-0.0091 Ωin the strain range of 0-190%. They also exhibited stable electrical conductivity, as well as excellent flexibility, which remained even when the fabric was stretched, shrunk, or bent. The results show that the electrically conductive fabric can be used as a smart textile, especially in fields associated with weaving, clothing, food products, lifestyle products, medicine, biology, electronics, aviation, and military equipment and accessories.展开更多
基金Supported by the Innovation and Technology Fund of Hong Kong, China
文摘AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium 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： IMP stimulated a conoentration-dependent rise in ISCl, 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 Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） 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 （10μmol/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.
文摘In this study, we combined silver nanowires with cupro fabrics using a dipping- drying method to prepare electrically conductive fabrics. The silver nanowires were first adhered to and then absorbed by microfibers to form electrically conductive fibers. They also filled the gaps and spaces between the microfibers, and were stacked or piled together to form networks with high electrical conductivity. The electrically conductive fabric had low resistance and good stretchability, e.g., 0.0047-0.0091 Ωin the strain range of 0-190%. They also exhibited stable electrical conductivity, as well as excellent flexibility, which remained even when the fabric was stretched, shrunk, or bent. The results show that the electrically conductive fabric can be used as a smart textile, especially in fields associated with weaving, clothing, food products, lifestyle products, medicine, biology, electronics, aviation, and military equipment and accessories.
