【作者】 苏月菊；

【导师】 沈赞明； 陈杰；

【作者基本信息】 南京农业大学 ， 基础兽医学， 2003， 硕士

【摘要】 本试验包括两部分：1、从体外到体内进行了胰岛素样生长因子Ⅰ（IGF-Ⅰ）对新生反刍动物瘤胃上皮生长发育影响的理论研究；2、依据前面的理论研究结果，寻找IGF-Ⅰ的替代品进行生产试验研究。 一、五肽胃泌素和IGF-Ⅰ对瘤胃上皮生长发育和更新的影响 1、应用体外瘤胃上皮细胞培养技术研究三种剂量五肽胃泌素(10^-11M、10^-10M和10^-9M)对新生奶公犊和成年奶牛瘤胃上皮细胞生长的影响。发现三种剂量均未提高新生奶公犊瘤胃上皮细胞DNA合成；而对于成年奶牛，10^-10M和10^-9M组DNA合成则有一定的增加，分别增加23.28％（P=0.21）和10.76％（P=0.14）；10^-11M组DNA合成与对照组接近，无明显效应。 2、用25ng／ml、100ng／ml、200ng／ml三种剂量IGF-Ⅰ处理体外培养新生奶公犊瘤胃上皮细胞，发现三种剂量组DNA合成分别增加26.52％（P＜0.01）、70.10％（P＜0.05）和53.16％（P＜0.01）。用25ng／ml、50ng／ml、100ng／ml、200ng／ml四种剂量IGF-Ⅰ处理体外培养成年奶牛瘤胃上皮细胞，可见25ng／ml和50ng／ml两种剂量能显著促进DNA合成，100ng／ml组亦促进DNA合成；与对照组相比，25ng／ml组、50ng／ml组和100ng／ml组DNA合成分别增加14.84％（P＜0.05）、13.26％（P＜0.05）和12.73％（P=0.16），而200ng／ml组略有降低（5.27％），但差异不显著（P=0.56）。 本系列研究结果显示：五肽胃泌素和IGF-Ⅰ对瘤胃上皮细胞DNA合成的影响具有明显的年龄特点。五肽胃泌素促进成年奶牛瘤胃上皮细胞DNA合成；但对新生奶公犊瘤胃上皮细胞DNA合成无促进作用。IGF-Ⅰ对新生和成年奶牛瘤胃上皮细胞DNA合成都有促进作用，但IGF-Ⅰ的促DNA合成幅度以犊牛较高。 二、口服rhIGF-Ⅰ粗制品对新生羔羊瘤胃上皮生长发育的影响 试验选用4对14日龄本地品种羔羊为研究对象，按体重接近配对原则，分为对照和试验组。试验组每日奶瓶饲喂rhIGF-Ⅰ粗制品5g／kg体重（含rhIGF-Ⅰ 1mg），持续10天。结果显示，口服rhIGF-Ⅰ粗制品组羔羊瘤胃上皮乳头数显著增加，上皮组织苏月菊:胰岛索样生长因子一I对新生反2勺动物瘤胃上皮生长发育的调节总DNA和总RNA分别提高31ry0（P<0 .01）和14.55%（P=O.217）;体外研究显示，试验组羔羊瘤胃上皮细胞DNA合成也明显增加。体内外研究结果一致。 结果提示，口服rhIGF江粗制品促进新生羔羊瘤胃上皮乳头发育;刺激瘤胃上皮细胞分裂，增加细胞数量，对单个细胞体积的影响相对较小。三、口服半肤胺（cS）对羔羊生长的影响1、选用4对14日龄本地品种羔羊为研究对象，按体重接近配对原则，分为对照组和试验组。14日龄开始，试验组每天口服CS gmg/kg体重，持续35天。结果显示，口服CS组羔羊体增重增加16.87%（P二0.16）;瘤胃上皮组织DNA含量略有增加。2、选用6对2月龄波杂二代断奶双羔，全公，同胞配对，分为对照组和试验组。试验组每天口服CS 9 mg/kg体重，持续24天。结果显示，口服CS组羔羊体增重增加8.32% （P<0 .05）。 本部分研究结果表明:CS对哺乳期和断奶早期羔羊生长都有促进作用;CS有刺激哺乳期羔羊瘤胃上皮细胞增殖的趋势。更多还原

【Abstract】 In this thesis, effect of insulin like growth factor I (IGF-I) on rumen epithelium growth and development was studied in vitro and vivo. And the substitute of IGF-I has been probed. I. Effect of Pentagastrin and IGF-I on the development and renewal of rumen epithelium.1. Pentagastrin at the concentration of 0 (control), 10-11M, 10-10M and 10-9M were administrated to the cell culture of neonatal male calfs and adult dairy cows. It was found that none of the three doses (10-11M, 10-10M and 10-9M) increased the DNA synthesis of rumen epithelial cells (REC) in neonatal male calfs. But in adult dairy cows, 10-10M and 10-9M exhibited an increase of DNA synthesis by 23.28% (P=0.21) and 10.76% (P=0.14), respectively; compared with the control, 10-11M had no significant difference.2. IGF-I at the concentration of 0 (control), 25ng/ml, 100ng/ml and 200ng/ml were administrated to the cell culture of neonatal male calfs. It was found that all of the three doses (25ng/ml, 100ng/ml and 200ng/ml) increased the REC DNA synthesis by 26.52%(P<0.01), 70.10%(P<0.05), and 53.16%(P<0.01), respectively. Using 0(control), 25ng/ml, 50ng/ml, 100ng/ml and 200ng/ml IGF-I in the culture of dairy REC. It was found that 25ng/ml and 50ng/ml exhibited a significant improve of DNA synthesis; the dose of 100ng/ml increased the DNA synthesis, but didn’t arrived the significant level. Compared with control, the DNA synthesis of 25ng/ml, 50ng/ml and 100ng/ml were increased by 14.84% (P<0.05) , 13.26% (P<0.05) and 12.73%(P=0.16), respectively; and 200ng/ml exhibited a little fall.These experiments provide the evidences that the effect of Pentagastrin and IGF-I on the development and renewal of REC has age character. Pentagastrin promotes DNA synthesis of REC in adult cow. But it has no significant elevation in neonatal calfs. IGF-I improves DNA synthesis of REC both in neonatal calfs and in adult cows. But the sensitivity of IGF-I in neonatal calfs is highter than that in adult cows.II. Effect of crude rhIGF-I preparation on the growth and development of rumen epithelium in neonatal lambs.Eight native suckled lambs were divided into 2 groups based on their weight. The treated group received crude rhIGF-I (1mg·kg-1·day-1) preparation and the control received distilled water from14d to 24d after birth. Lambs were killed and rumen epithelium was collected. The tissue was used to study [3H] thymidine incorporation in vitro, analyse its DNA, RNA content, and the change of its paillae. It was found that oral administration of crude rhIGF-I preparation increased the DNA content significantly by 31%(P<0.01) compared with the control group. And the RNA content was improved by 14.55%(P=0.217), but not on significant level. The number of paillaes was increased.These results demonstrate that oral administration of crude rhIGF-I preparation froml4d to 24d after birth significantly increased rumen epithelium growth and development in suckled neonatal lambs.III. Effect of oral administrated of cysteamine (CS) on the growth in neonatal lambs.Eight native suckled lambs were divided into 2 groups based on their weight. Thetreated group were oral infused with CS (9mg · kg-1· day-1) and the control with distilledwater from14d to 49d after birth. Result showed that CS increased weight gain by 16.87%(P=0.16). The DNA content of rumen epithelium was increased a little. And no significantchange was found on the RNA content of rumen epithelium.Twin 2-month-old unsuckled lambs (n=6) received CS (9mg· kg-1 · day-1) for 24 days. Result showed that CS increased weight gain by 8.32% (P<0.05) .These results demonstrate that oral administration of CS increased weight gain both in suckled and unsuckled lambs. It seemed that oral CS increased rumen epithelium growth and development in suckled neonatal lambs.更多还原