| Inflammatory bowel disease (IBD) is a group of chronic intestinal inflammatory disease, whose etiology is unknown. There is no curative treatment. Thus it is essential to search for new drugs with good curative effects but few side effects. Many studies indicate that there is immune regulation disfunction damage. It may be associated with an inability of the intestinal mucosa to protect itself from luminal challenges and/or inappropriate repair following intestinal injury. Numerous cell populations regulate these broad process including epidermal growth factor (EGF). Therefore EGF has been used on experimental IBD and achieved some curative effects. EGF has a protective effect on gastrointestinal mucosa. Its main mechanism is promoting mitosis, cytoprotection, increasing the mucosa DNA, RNA and albumin content, and stimulating the growth and the repairment of tissue. EGF activates its receptor to control intestinal cell hyperplasia. Its treatment effect on the gastrointestinal disease has received more and more attention. It has significant scientific value and potential economic value both in basic theory and clinical medicine. However, currently vestment in EGF production is not financially profitable. In our study we used EGF prepared and purified from goat submaxillary gland whose source is abundant. Therapeutic trail of goat submaxillary gland EGF is based on the well setting up steady IBD rat model. It's therapeutic effect of pathological changes on rat colon mucosa was observed, and its possible mechanism was discussed. In this study, our goal is to study its industrialization and clinical uses.Materials & Methods1. Goat submaxillary gland freeze-dry powder was extracted by HAC, chromatographed by Sephadex G15 gelatin and DEAE Sphacel chromatography column and then it's molecular weight was analyzed by SDS-PAGE electrophoresis. The goat EGF biological activity was measured by experiment of ELISA, MTT and mice eyelids opening and their teeth growing.2. Healthy, sexual-mature, and male Sprague-Dawley rats weighing 250~280g were tested. Colitis was induced with acetic acid enemas. After the rats fasting for 24 hours, 2ml of 7% acetic acid diluted with saline was instilled into the colon using 2cm diameter enemator, 8cm proximal to the anus. After 15 seconds of surface contact, the acidic solution was withdrawn and the lumen flushed with 5ml saline.3. The experimental rats randomly were randomly dividedly into 3 groups, i. e., model, saline control and EGF-treated group. In the model group, rats were fed and had no enema for 7 days after induction of colitis. In the saline control group, fasted rats had a 2ml saline enema each morning for 7 days after induction of colitis. In the EGF- treated group, 270ug goat EGF enema dissolved in saline to a total volume of 2ml was instilled into each fasted rat colon every morning for 7 days after induction of colitis.4. All fasted experimental rats were executed by subluxation of cervical vertebra and thelower gastrointestinal tract was excised after 7 days. The colon for morphological examination was cut 8cm proximal to the anus. The colon was rapidly excised, opened along its mesenteric border, and gently rinsed of its luminal contens with saline. The colon was then placed flat with mucosal surface upward, on a foamy plate. The samples were calculated mucosa impairment scores and photographed by digital camera. Thereafter, the samples were fixed in 10% buffered formaldehyde. For light microscopy, 5um, formaldehyde-fixed, paraffin-embedded sections were stained with H&E. Mucosa impairment score for pathologic histology was evaluated.5. Myeloperoxidase (MPO) activity was examined in an additional 300mg rat samples. Subsequent to weighing on a analytical balance, the colon segment was suspended in 0.5% hexadecyltrimethyl- ammonium bromide (PH 6.0; 50mg of tissue per milliliter) and was then homogenized for 30 seconds using a generator. After freeze-thawing the homogenate 15min, the tissue levels of MPO activity were determin...
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