The Effect And Mechanism Of L-Fucose In Inhibiting Spontaneous Contraction Of Colon Smooth Muscle Strips

Part ? Impact of L-fucose on spontaneous contraction of isolated colon smooth muscle stripsObjective:Sucrose as a control,to define the impact of L-fucose on spontaneous contraction of colon smooth muscle strips from human and rat,and make sure the dose-effect of L-fucose,and the effect of L-Fucose on spontaneous contractions of muscle strips in spasticity(treated by Ach).Materials and methods:(1)The osmotic pressure of sucrose groups(control)and fucose groups with various concentration were measured by Vapro(?)5600 osmotic pressure gauge.(2)The impact of L-Fucose on spontaneous contractions of proximal,distal colonic longitudinal muscles of SD male rats,distal colon circular muscles of SD male rats,and human colon longitudinal muscles strips were examined by Organ Bath system.(3)To confirm the impact of L-Fucose on spontaneous contractions of distal colon longitudinal muscles of SD male rats when they were in spasticity(treated with ACH 10-5 M).Result:(1)Before muscle strips experiment,the osmotic pressure of sucrose groups which concentration range of sucrose was 0.5%-4.0%and fucose groups which concentration range of fucose was 0.25%-2%were tested to make sure that the two groups had the same osmotic pressure(p>0.05).(2)Isolated muscle strips experiment showed L-fucose with a concentration range of 0.25%-1.5%had a significant inhibition effect on spontaneous contraction of distal colon longitudinal muscles of rats.The inhibition effect increased gradually with increasing concentration(p<0.05),and the inhibition effect of L-fucose with each concentration were significantly higher than the sucrose control group.L-fucose also significant decrease spontaneous contractions of proximal colonic longitudinal muscle strips and distal colon circular muscle strips from rat.And human colonic longitudinal muscle strips.(3)When treated by 10-5 M Ach Chloride,isolated distal colon longitudinal muscle strips of rats turn into spasticity.Concentration of L-Fucose more than 1%could also inhibit its spontaneous contractile activity.Conclusion:Compared with sucrose,L-fucose significantly inhibited spontaneous contraction of distal colon longitudinal muscle of rats in a dose-dependent manner.L-fucose also decrease the spontaneous contraction of proximal colon longitudinal muscle strips and distal colon circular muscle strips from rat.Also the human colon longitudinal muscle strips.When isolated distal colon longitudinal muscle strips of rats turn into spasticity by treating with exogenous Ach Chloride,L-Fucose could also inhibit its spontaneous contractile activity.Part ? Mechanism of L-Fucose in inhibiting spontaneous contraction of isolated colon longitudinal muscle stripsObjective:To determine the expression of L-Fucose in intestinal tract,and the intestine permeability of L-Fucose,Further more the mechanism of L-fucose in inhibiting spontaneous contraction of rat colon longitudinal muscle strips.Materials and methods:(1)The frozen sections of distal colon muscle tissue of SD male rats were stained by fluorescence and then observed under confocal microscope to determine the expression of L-Fucose in intestinal tract.(2)The mucosal permeability of L-Fucose was measured by Ussing Chamber technology combined with spectrophotometer.(3)The isolated smooth muscle strips were first incubated with sodium channel blocker TTX and nitric oxide synthase(NOS)inhibitor L-NAME,SMT and 7-NI,and then L-Fucose was added into organ bath.The effect of L-Fucose on spontaneous contraction of muscle strips was observed.Result:(1)L-fucose is massive expression in the surface of intestinal epithelial cells and luminal mucin by fluorescence stained.(2)To Detect the permeability of L-fucose by Ussing Chamber Technology,added the apical side of 1%L-Fucose,and the basal side L-Fucose concentration increased gradually within 120min(P<0.05),and the concentration of 120min was 38.91±10.75mg/L.(3)Muscle strips were separately incubated with 10-5g/L TTX and 10-4 M total NOS inhibitor L-NAME by 20min and above,than added 0.5%,1%,1.5%L-Fucose,compared with the control group,the ability of L-Fucose to inhibit the spontaneous contraction of muscle strips was significantly decreased(P<0.05);while incubated with the iNOS inhibitor 10-3 M SMT did not influence the inhibition ability of L-Fucose(P>0.05);incubated with 10-5 M nNOS inhibitor 7-NI also inhibit the effect of L-Fucose on spontaneous contraction of muscle strips.Conclusion:L-fucose is massive expression in the surface of intestinal epithelial cells and luminal mucin and free L-fucose can get through the mucous layer;The effect of L-Fucose inhibit muscle contraction may be dependent on Enteric nervous system(ENS);and the Mechanism to inhibit smooth muscle contraction may through induction of neuronal Nitric Oxide Synthase(nNOS)to produce NO,and promote smooth muscle strips relaxation.