In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhanc...In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b). The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC) and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c). The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d). Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e). The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.展开更多
We recently reported that L-ascorbic acid 2-phosphate (AP) stimulates the growth of human dermal papilla (DP) cells, induces secretion of IGF-1 from the DP cells to promote hair shafts elongation in cultured human hai...We recently reported that L-ascorbic acid 2-phosphate (AP) stimulates the growth of human dermal papilla (DP) cells, induces secretion of IGF-1 from the DP cells to promote hair shafts elongation in cultured human hair follicles, and triggers early progression from the telogen to anagen phase in mice. Since the magnesium salt of AP (APMg) is a highly hydrophilic ionic molecule, it is not easy to deliver this reagent to the skin or hair follicles by topical application alone. In order to enhance skin penetration of APMg without changing any molecular properties, a non-invasive iontophoretic delivery method was introduced. Iontophoresis of the negatively charged APMg under the electrode bearing same charge (cathode) significantly enhanced the in vitro penetration of APMg into a Franz cell equipped with mouse dorsal skin. In contrast, iontophoretic movement with the anode inhibited APMg penetration achieved with passive diffusion alone. The effect of iontophoresis on enhancing the penetration of APMg was also found to be much higher in the skin of hairy mice (3 - 8 times) compared to hairless mice (1.5 - 2.5 times). These findings indicated that iontophoretic movement induced the transfollicular pathway more strongly and effectively than the transdermal pathway. This phenomena was also demonstrated by the in vivo iontophoretic delivery of sodium fluorescein using hairy and hairless mice. The degree of iontophoretic enhancement during APMg penetration was also dependent on various conditions such as current density and application duration.展开更多
Salicylic acid （SA） was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H...Salicylic acid （SA） was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H2O2-metabolizing enzymes in rice seedlings under lead stress were studied. When rice seedlings grown in nutrient solution containing Pb^2＋ （0, 0.05, 0.15, 0.25 mmol/L） for 18 d, the plant biomass as well as the chlorophyll content of leaves decreased with increasing Pb concentration. The pre-treatment with SA （treated with 0.1 mmol/L SA for 48 h before Pb stress） partially protected seedlings from Pb toxicity. The chlorophyll contents were significant higher in leaves of Pb-exposed with SA pre-treatment seedlings than in Pb-exposed plants at the same Pb intensity. SA pre-treated alone could significantly increase the length of shoot and root of seedlings but the vigour difference was not marked under long-term exposure to Pb toxicity. SA pre-treated influence the H2O2 level in leaves of seedlings by up-regulating the activity of superoxide dismutase （SOD）, repressing the activity of catalase （CAT） and ascorbate peroxidase （APX） depending on the concentrations of Pb^2＋ in the growth medium. The results supported the conclusion that SA played a positive role in rice seedlings against Pb toxicity.展开更多
文摘In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b). The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC) and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c). The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d). Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e). The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.
文摘We recently reported that L-ascorbic acid 2-phosphate (AP) stimulates the growth of human dermal papilla (DP) cells, induces secretion of IGF-1 from the DP cells to promote hair shafts elongation in cultured human hair follicles, and triggers early progression from the telogen to anagen phase in mice. Since the magnesium salt of AP (APMg) is a highly hydrophilic ionic molecule, it is not easy to deliver this reagent to the skin or hair follicles by topical application alone. In order to enhance skin penetration of APMg without changing any molecular properties, a non-invasive iontophoretic delivery method was introduced. Iontophoresis of the negatively charged APMg under the electrode bearing same charge (cathode) significantly enhanced the in vitro penetration of APMg into a Franz cell equipped with mouse dorsal skin. In contrast, iontophoretic movement with the anode inhibited APMg penetration achieved with passive diffusion alone. The effect of iontophoresis on enhancing the penetration of APMg was also found to be much higher in the skin of hairy mice (3 - 8 times) compared to hairless mice (1.5 - 2.5 times). These findings indicated that iontophoretic movement induced the transfollicular pathway more strongly and effectively than the transdermal pathway. This phenomena was also demonstrated by the in vivo iontophoretic delivery of sodium fluorescein using hairy and hairless mice. The degree of iontophoretic enhancement during APMg penetration was also dependent on various conditions such as current density and application duration.
基金Project supported by the National Key Basic Research and Development Program (No. 2002CB410804) the National Natural Science Foundation of China (No. 30671255).
文摘Salicylic acid （SA） was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H2O2-metabolizing enzymes in rice seedlings under lead stress were studied. When rice seedlings grown in nutrient solution containing Pb^2＋ （0, 0.05, 0.15, 0.25 mmol/L） for 18 d, the plant biomass as well as the chlorophyll content of leaves decreased with increasing Pb concentration. The pre-treatment with SA （treated with 0.1 mmol/L SA for 48 h before Pb stress） partially protected seedlings from Pb toxicity. The chlorophyll contents were significant higher in leaves of Pb-exposed with SA pre-treatment seedlings than in Pb-exposed plants at the same Pb intensity. SA pre-treated alone could significantly increase the length of shoot and root of seedlings but the vigour difference was not marked under long-term exposure to Pb toxicity. SA pre-treated influence the H2O2 level in leaves of seedlings by up-regulating the activity of superoxide dismutase （SOD）, repressing the activity of catalase （CAT） and ascorbate peroxidase （APX） depending on the concentrations of Pb^2＋ in the growth medium. The results supported the conclusion that SA played a positive role in rice seedlings against Pb toxicity.
