饲料中添加烟酸铬对肥育猪生长和代谢的影响

将20头杜长大肥育猪随机分成试验组和对照组,试验组日粮添加200μg·kg-1烟酸铬(以Cr元素计)作85天饲喂试验。结果表明:(1)试验组日增重比对照组提高10.9%;料重比下降6%。(2)添加烟酸铬对血清中钾、钠、氯化物、镁、总蛋白、白蛋白、高密度脂蛋白、谷草转氨酶、谷丙转氨酶、乳酸脱氢酶、α-羟丁酸脱氢酶、直接胆红素、总胆红素、IgG、IgM无影响(P>0.05);血清中钙、磷、铁、葡萄糖、尿素氮、尿酸、甘油三脂、总胆固醇、血红蛋白、磷酸肌酸激酶和肌酐的含量显著下降;碱性磷酸酶含量显著升高(P<0.01)。(3)猪体组织Cr含量均未超过国家限量标准。(4)猪体各器官组织正常。由此可见,在生长肥育猪中添加一定量铬制剂对猪有正面效应。

Synergistic effect of all-trans-ret inoic acid and arsenic trioxide on growth inhibition and apoptosis in human hepatoma, breast cancer, and lung cancer cells in vitro

AIM： To investigate the effect of all-trans-retinoic acid （ATRA） on arsenic trioxide （As2O3）-induced apoptosis of human hepatoma, breast cancer, and lung cancer cells in an attempt to find a better combination therapy for solid tumors. METHODS： Human hepatoma cell lines HepG2, Hep3B, human breast cancer cell line MCF-7, and human lung adenocarcinoma cell line AGZY-83-a were treated with As203 together with ATRA. Cell survival fraction was determined by MTT assay, cell viability and apoptosis were measured by annexin V-fluorescein isothiocyanate （FITC） and PI staining, and intracellular glutathione （GSH） and glutathione-S-transferase （GST） activities were determined using commercial kits. RESULTS： Cytotoxicity of ATRA was low. ATRA （0.1, 1, and 10 μmol/L） could synergistically potentiate As2O3 to exert a dose-dependent inhibition of growth and to induce apoptosis in each of the cell lines. HepG2 and Hep3B with low intracellular GSH or GST activities were remarkably sensitive to As2O3 or As2O3＋ATRA, while AGZY-83-a with higher GSH or GST activities was less sensitive to As2O3 or As2O3＋ATRA. Treatment with 2 μmol/L As2O3 for 72 h significantly decreased intracellular GSH and GST levels in each of the cell lines, and 1 μmol/L ATRA alone reduced minimal intracellular GSH and GST levels. ATRA potentiated the effect of As2O3 on intracellular GSH levels, but intracellular GST levels were not significantly affected by the combination of As2O3 and ATRA for 72 h as compared to As2O3 alone.CONCLUSION： ATRA can strongly potentiate As2O3- induced growth-inhibition and apoptosis in each of the cell lines, and two drugs can produce a significant synergic effect. The sensitivity to As2O3 or As2O3＋ATRA is inversely proportional to intracellular GSH or GST levels in each of the cell lines. The GSH redox system may be the possible mechanism by which ATRA synergistically potentiates As203 to exert a dose-dependent inhibition of growth and to induce apoptosis. 2005 The WJG Press and Elsevier Inc. All rights reserved.

Growth-Promoting Effects of Liposome-Encapsulated Porcine Somatotropin in Mice

[ Objective] To study growth-promoting effects of liposome-encapsulated porcine somatotropin （pST） and its sustained-release effects in mice. [ Method] The mice were randomly divided into experimental groups and control group. The mice in the experimental groups were respective- ly administrated with pST and liposome-encapsulated pST via intraperitoneal injection, and those in the control group were administrated with saline. They were weighed on Day 7, 14 and 28, and the growth rate was calculated. [ Result] The growth of mice had significant difference between the experiment groups and control group （P 〈 0.05）, which indicated that the pST and liposome-encapsulated pST had growth-promoting effects in mice, and the liposome-encapsulated pST had sustained-release effects. [Condusion] The liposome-encapsulated pST can promote the growth of animal and its sustained-release peried is 7 d.