Different Pregnancy Application Of L-arginine In The Iugr Rat

Intrauterine Growth Retardation is a serious complication in obstetrics and an important cause of perinatal mortality. Children with a history of IUGR may possibly have a negative effect on brain growth and metal development. The IUGR condition is most commonly caused by inadequate maternal - fetal circulation, with a resultant decrease in fetal blood, oxygen and nutrition supply. Recently, people pay more attention to NO ( nitric oxide) . NO is synthesized from the amino acid L - arginine. It has been proved that L - arginine can increase the average body weight of live fetal rats. But the effect of using L - arginine during different gestation has not been reported as far. In this trial, by way of passive smoking, we established IUGR SD rats model. By studying the effect of using L - arginine during different gestation we could find the efficient opportunity.Material and MethodsThe mature and healthy virgin SD rats whose body weight is 250 -350g were selected. The IUGR pregnant rat models are set up by way of passive smoking. The pregnant SD rats were randomly divided into five groups; normal group pregnant rats were raised in normal situation without passive smoking. Control group pregnant rats were raised in the passive smoking chamber for two hours per day but no passive smoking during all gestation. Model group were raised in the chamber for two hours per day with passive smoking during all gestation ; Medium - term group were raised in the same situation as modelgroup but with L - arginine using (0. 5g·kg-3·d-1)for five days from 8th day of pregnancy; Terminal group had the same situation as medium -term group except that we started its using from 15th day of the pregnancy. There was no difference in food or water intake among all of these groups, and they were raised in the same situation.The passive smoking chamber was manufactured referring to Duan Tiao. The chambers size is 0. 5 x 0. 5 x 1m3, closed, but with installation that gas can go into or out of the chamber. There is blast stoma on one side of the chamber and there is a stoma letting out wind on the other side of the chamber. The two stomas are connected with a airtight pipe that is plastic. We lighted three cigarettes every time in 20 minutes then closed the chamber. The pregnant SD rats stayed in this condition for 2h. We detect the concentration of CO as the index of smoke. The concentration of CO in the chamber was stable within the 2 hours.1ml sample of blood were collected in the 20th day of the pregnancy and centrifuged at 3500rpm for 15 minutes. The serum was stored at - 80癈 for later analysis. We assayed the concentration of nitric oxide in blood by nitrite reductase.We dissected the pregnant rats in the 20th day of pregnancy. The rats whose live fetal rats were more than 12 or less than 6 are excluded. We recorded the body weight of each live fetal rats and calculate the means.The diagnosis criterion of IUGR is the average body weight of live fetal rats of normal group minus 2 standard deviation.Data were analyzed with t - test and x - test.ResultsThere is significant difference between the normal group (2.534 ±0. 250g) and the model group (2. 210 ±0. 164g) , P < 0. 001; There is significant difference between the terminal group (2.390 ±0. 320g) and model group, P <0. 05 ; This demonstrates L - arginine is effective to IUGR; There is significant difference between medium -term group and terminal group, P <0. 001; This demonstrates that the effect of using L - arginine during medium - term pregnancy is better than that of terminal group. There is significant difference between model group (18.06% ) and normal group (2^82% ) in incidence of IUGR. There is also significant difference between model group and L -arginine using group (1.35% , 6.41% ) , P <0.05.There is significant difference between model group ( 86. 4 ± 9. 0mmo]/L) and normal group (110. 8 ± 19. 8mmol/L) in concentration of nitric oxide in blood, P < 0. 001; There is also significant difference between model group and...