AIM:To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.METHODS:Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment(JSMF) were ...AIM:To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.METHODS:Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment(JSMF) were established.Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside,and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.RESULTS:Stimulatory effects on the contractility of JSMF were induced(45.3% ± 4.0% vs 87.0% ± 7.8%,P < 0.01) by deslanoside in 8 low contractile states,and inhibitory effects were induced(180.6% ± 17.8% vs 109.9% ± 10.8%,P < 0.01) on the contractility of JSMF in 8 high contractile states.The effect of deslanoside on the phosphorylation of myosin light chain of JSMF in low(78.1% ± 4.1% vs 96.0% ± 8.1%,P < 0.01) and high contractile state(139.2% ± 8.5% vs 105.5 ± 7.34,P < 0.01) was also bidirectional.Bidirec-tional regulation(BR) was abolished in the presence of tetrodotoxin.Deslanoside did not affect jejunal contractility pretreated with the Ca 2+ channel blocker verapamil or in a Ca 2+-free assay condition.The stimulatory effect of deslanoside on JSMF in a low contractile state(low Ca 2+ induced) was abolished by atropine.The inhibitory effect of deslanoside on jejunal contractility in a high contractile state(high Ca 2+ induced) was blocked by phentolamine,propranolol and L-NG-nitroarginine,respectively.CONCLUSION:Deslanoside-induced BR is Ca 2+ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.展开更多
We previously developed an HPLC method for determination of lanatoside C, digoxin and α-acetyldigoxin in digitalis glycosides isolated from Digitalis lanata leaves. Here, we present an improved HPLC-UV method to dete...We previously developed an HPLC method for determination of lanatoside C, digoxin and α-acetyldigoxin in digitalis glycosides isolated from Digitalis lanata leaves. Here, we present an improved HPLC-UV method to determine those compounds and deslanoside. We used the improved method to examine the effects of various pretreatments on the amounts of the four compounds isolated from the leaves, with the aim of maximizing the yield of digoxin. Leaves were extracted with 50% methanol, followed by clean-up on a Sep-Pak C18 cartridge prior to HPLC analysis. The amounts of lanatoside C, digoxin and α-acetyldigoxin per 100 mg of the leaves without pretreatment were 115.6, 7.45 and 23.8 μg, respectively (deslanoside was not detected). Pretreatment with acetic acid, which activated deglucosylation mediated by digilanidase present in the leaves, increased the amounts of digoxin and α-acetyldigoxin, while lanatoside C and deslanoside were not detected. Pretreatment with sodium methoxide, which hydrolyzed lanatoside C to deslanoside, increased the yields of deslanoside and digoxin, while lanatoside C and α-acetyldigoxin were not detected. The combination of both pretreatments afforded only digoxin in a yield of 115.1 μg/100 mg leaves. Use of the combined pretreatments appears to be effective for maximizing the yield of digoxin from the leaves.展开更多
基金Supported by National Natural Science Foundation of China,No. 30772601
文摘AIM:To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.METHODS:Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment(JSMF) were established.Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside,and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.RESULTS:Stimulatory effects on the contractility of JSMF were induced(45.3% ± 4.0% vs 87.0% ± 7.8%,P < 0.01) by deslanoside in 8 low contractile states,and inhibitory effects were induced(180.6% ± 17.8% vs 109.9% ± 10.8%,P < 0.01) on the contractility of JSMF in 8 high contractile states.The effect of deslanoside on the phosphorylation of myosin light chain of JSMF in low(78.1% ± 4.1% vs 96.0% ± 8.1%,P < 0.01) and high contractile state(139.2% ± 8.5% vs 105.5 ± 7.34,P < 0.01) was also bidirectional.Bidirec-tional regulation(BR) was abolished in the presence of tetrodotoxin.Deslanoside did not affect jejunal contractility pretreated with the Ca 2+ channel blocker verapamil or in a Ca 2+-free assay condition.The stimulatory effect of deslanoside on JSMF in a low contractile state(low Ca 2+ induced) was abolished by atropine.The inhibitory effect of deslanoside on jejunal contractility in a high contractile state(high Ca 2+ induced) was blocked by phentolamine,propranolol and L-NG-nitroarginine,respectively.CONCLUSION:Deslanoside-induced BR is Ca 2+ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.
文摘We previously developed an HPLC method for determination of lanatoside C, digoxin and α-acetyldigoxin in digitalis glycosides isolated from Digitalis lanata leaves. Here, we present an improved HPLC-UV method to determine those compounds and deslanoside. We used the improved method to examine the effects of various pretreatments on the amounts of the four compounds isolated from the leaves, with the aim of maximizing the yield of digoxin. Leaves were extracted with 50% methanol, followed by clean-up on a Sep-Pak C18 cartridge prior to HPLC analysis. The amounts of lanatoside C, digoxin and α-acetyldigoxin per 100 mg of the leaves without pretreatment were 115.6, 7.45 and 23.8 μg, respectively (deslanoside was not detected). Pretreatment with acetic acid, which activated deglucosylation mediated by digilanidase present in the leaves, increased the amounts of digoxin and α-acetyldigoxin, while lanatoside C and deslanoside were not detected. Pretreatment with sodium methoxide, which hydrolyzed lanatoside C to deslanoside, increased the yields of deslanoside and digoxin, while lanatoside C and α-acetyldigoxin were not detected. The combination of both pretreatments afforded only digoxin in a yield of 115.1 μg/100 mg leaves. Use of the combined pretreatments appears to be effective for maximizing the yield of digoxin from the leaves.
