| Neonatal asphyxia is a common disease during perinatal, which happens in uterus and during labouring with a high morbidity and mortality in newborn. It may lead to damages of many organs such as heart, brain, kidney and gastrointestine. Among which, the rate of gastrointestinal injury is 33% and even higher than brain damage. It is also noted in clinic that asphyxiated neonates are susceptible to complicate gastrointestinal dysfunction even NEC. Although it is not a vital organ, the gastrointestine plays an important role in digestion and absorption. It provides necessary energy and nutrition to the body and has significant importance in maintaining normal metabolism and growth. However, little research has been done on the mechanism of how the intestinal mucosal defense matured, injuried and repaired in illness.Intestinal trefoil factor (ITF) is a member of trefoil peptide family , which is important in maintenance and repairment of the intestinal mucosal barrier. Its physiological function presents in two aspects;First, ITF may interact with the mucus, stabilize the mucus gel by perhaps interacting with intestinal mucin and increasing the viscosity. Second, it is shown to be a motogen, i. e, it can stimulate cell migrating and proliferating, promote epithelial cell repairmen! and ITF expresses in early phase of injury, so it is important in the self - protection mechanism of intestine.Proliferating cell nuclear antigen ( PCNA) is also called cyclin, a kind of intranuclear protein, which is a assistant protein of DNase. Its synthesis and expression are associated with cell proliferation and probably can regulate DNA duplication. PCNA is a perfect cell proliferating index in normal proliferating and certain tumor tissue. PCNA has already been used as a routing method to test proliferating cell at present. Our study is designed to explore the principle of ITF expression and the relationship between ITF and intestinal damage and re-pairment after intrauterine hypoxia so as to understand the mechanism of intestinal injury and find a new way to prevent and treat gastrointestinal disease.Material and Methods1. Animal ModelThe models of intrauterine acute ischemia were made by clamping one side of vessels supplying blood to uterus of Wistar rats of 21 gasta-tional days for 20 minutes. Another side was regarded as sham operation group. When reaching prescribed time, uterus horn was opened rapidly and pups were removed. For establishing normal breath as fast as possible, the fetal rats were cleaned the respiratory tract and stimulated breath. The baby rats were fed by the other female rats for 0,24, 48 and 72 hours, respectively, then sacrificed. Intestines were taken away and stored in different styles.2. Methods;(1) ITFmRNA were detected by the method of reverse transcription polymerse chain reaction( RT - PCR). The density of bands was assessed and amount of ITFmRNA was determined as a radio to |B -actin.(2)The PCNA expression was measured by immunohistochemis-try method in different time point and using Meta Morph to analyze.(3 ) Intestinal tissue was studied histologically by HE staining in order to observe the areas and degree of injury and to value injury index.3. Statistics:Data was expressed as x ± s. Results were analysed with t test and LSD test (q test). Spearman method was used for correlation a-nalysis.Results1. RT - PCR showed that expression of ITF mRNA commenced in fullterm rats and increased with age. After ischemia, ITF mRNA expression began decreasing to the minimum by 24h (0.59 ±0.032) after birth, then increasing. At 72h after birth even higher than the control group (P<0.01).2. Study PCNA results showed that there was positive stain on fullterm rats which sited in intestinal mucosal goblet cell nuclear. The PCNA level had a remarkable decline at 48h (53. 29 ± 1.97) after ischemia. There was a significant difference between ischemic groupsand control groups ( P < 0.01).3. Histologic examinations of normal newborn rat show...
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