Investigation Of The Relationships With Gastric Motility,Vasculopathy, And Smooth Muscle Contractile In Diabetic Rats

Objective:To investigate the relationship of Gastric motility, vasculopathy, and smooth muscle contraction function in diabetic ratsMethods:1. Establish animal models:A total of50male SPF rat were first divided into randomly in two groups:control group(n=20) and diabetic mellitus group the (n=30).The rats in the DM group were induced by steptozotoin via Intraperitoneal injection.Than the experimental group were divided into four groups:A.4w DM group (n=13); B. early control group (n=10); C24w DM group (n=13); D.late control group (n=10).2. After modeling4weeks and24weeks, gastric emptymg(GET1/2) and gastric emptying rate were measured by single photon emission computed tomography (SPECT).3. The determination of isolated gastric smooth muscle contraction function:Gastric smooth muscle strips were isolated from stomach antrum, then immersed into Krebs solution and linked with tonotrans ducer to record their contraction.4. Determination of gastric vascular changes with immunohistochemical methods.5. Immunohistochemical method was used to examine the expression of CD34in gastric tissue, high magnification observation vascular morphology, determination of vascular density.Results:1. The gastric half-emptying time of group A was28.66±6.41min, compared with group B(48.67±8.52min),the half-emptying time was significantly shower(P＜0.01); The gastric half-emptying time of group C was83.37±21.48min,which is significantly longer than group D(49.59±10.60min, P<0.01). The gastric empty rate of group A was significantly speeding up than group B(1.83±0.4%min VS1.05±0.17%/min, P＜0.01); compared with group C and D The gastric empty rate was significantly slower(0.62±0.13%/min VS1.13±0.51%/min, P<0.01).2. The gastric smooth muscle contraction frequency and amplitude have no significant difference between group A(frequency:3.97±0.91times/min. amplitude329.26±90.68mg) and B(frequency:4.79±1.07times/min, amplitude417.2±74.28mg), however there have significant difference between group C and D, the gastric smooth muscle contraction frequency and amplitude of group C(frequency:3.20±0.82times/min, amplitude249.8±89.7mg) was lower than group D(frequency:4.33±0.95times/min, amplitude409±100.67mg).3. Observed on light microscope, Masson staining:the late stage of the diabetes group, vascular endothelial cell of submucous was shed, intimal injury, diameter ratio was reduced.The early state diabetic group did not change significantly, the microvascular density of gastric mucosal is increased first, and than reduced.Conclusion:1. In the early stage of diabetes mellitus gastric emptying is accelerated, with the progress of the disease the gastric emptying rate was gradually reduced, to the late stage of the diabetes the gastric emptying is gear down.2. In the process of diabetes, the smooth muscle contraction function is gradually reduced.3. With the progress of the diabetes, the microvascular density of gastric mucosal is increased first, and than reduced; small vascular of Subserosal was fibrosised gradually, diameter ratio was reduced.4. The change of the function of gastric smooth muscle contraction and vascular lesions may be the cause of diabetic gastric dynamic dysfunction.