Triptolide was given orally to adult male Sprague-Dawley rat sat a dosage of 75 μg/kg for 35 days.After 28 days of treatment,the result of mating tests showed that all the drug treated rats were infertile.At the end ...Triptolide was given orally to adult male Sprague-Dawley rat sat a dosage of 75 μg/kg for 35 days.After 28 days of treatment,the result of mating tests showed that all the drug treated rats were infertile.At the end of drug treatment,the density of caudal spermatozoa and the weight of cpididymis were reduced significantly.All the spermatozoa were immobile.There was no detectable damage of spermatogenesis and epididymal epithelia in triptolide treated rats under microscopical examination.However,modcrate and severe damage of spermatozoa were seen in the corpus and caudal epididymis.The content of cytosolic and nuclear dihydrotestosterone (DHT) receptors in the caput and caudal epididymides was increased but insignificantly as compared with that of the controls.However, the content of DHT receptor in the cytosal of the ventral prostate was elevated very,significantly (P< 0.01).This result suggests that one of the sitcs of action of triptolide might be the epididymis.展开更多
The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N‐heterocycles is a challenge.In this study,Ru_(2)P/AC effectively promoted reversible transformations bet...The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N‐heterocycles is a challenge.In this study,Ru_(2)P/AC effectively promoted reversible transformations between unsaturated and saturated N‐heterocycles affording yields of 98%and 99%,respectively.Moreover,a remarkable enhancement in the reusability of Ru_(2)P/AC was observed compared with other Ru‐based catalysts.According to density functional theory calculations,the superior performance of Ru_(2)P/AC was ascribed to specific synergistic factors,namely geometric and electronic effects induced by P.P greatly reduced the large Ru‐Ru ensembles and finely modified the electronic structures,leading to a low reaction barrier and high desorption ability of the catalyst,further boosting the hydrogenation and acceptorless dehydrogenation processes.展开更多
AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfi de (H2S) generation. METHODS: The regulation of CSE expression in respons...AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfi de (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5'-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension.展开更多
文摘Triptolide was given orally to adult male Sprague-Dawley rat sat a dosage of 75 μg/kg for 35 days.After 28 days of treatment,the result of mating tests showed that all the drug treated rats were infertile.At the end of drug treatment,the density of caudal spermatozoa and the weight of cpididymis were reduced significantly.All the spermatozoa were immobile.There was no detectable damage of spermatogenesis and epididymal epithelia in triptolide treated rats under microscopical examination.However,modcrate and severe damage of spermatozoa were seen in the corpus and caudal epididymis.The content of cytosolic and nuclear dihydrotestosterone (DHT) receptors in the caput and caudal epididymides was increased but insignificantly as compared with that of the controls.However, the content of DHT receptor in the cytosal of the ventral prostate was elevated very,significantly (P< 0.01).This result suggests that one of the sitcs of action of triptolide might be the epididymis.
文摘The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N‐heterocycles is a challenge.In this study,Ru_(2)P/AC effectively promoted reversible transformations between unsaturated and saturated N‐heterocycles affording yields of 98%and 99%,respectively.Moreover,a remarkable enhancement in the reusability of Ru_(2)P/AC was observed compared with other Ru‐based catalysts.According to density functional theory calculations,the superior performance of Ru_(2)P/AC was ascribed to specific synergistic factors,namely geometric and electronic effects induced by P.P greatly reduced the large Ru‐Ru ensembles and finely modified the electronic structures,leading to a low reaction barrier and high desorption ability of the catalyst,further boosting the hydrogenation and acceptorless dehydrogenation processes.
文摘AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfi de (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5'-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension.
