Drug residues in food animals. III. Plasma and tissue kinetics of potassium penicillin G in young cross-bred swine

Twenty-two young cross-bred swine were treated either intravenously or orally with potassium penicillin G. The pharmacokinetics of penicillin G were determined in plasma and tissues. The plasma half-life of penicillin G in swine was found to be 19.45±1.69 min, and the distribution and elimination kinetics were found to fit a classical two-compartment model. The volume of distribution was found to be 0.53±0.12 1/kg, and the body clearance was found to be 19.06±5.06 ml/min/kg which exceeded the effective renal plasma flow of 16.50±2.73 ml/min/kg, suggesting that the drug was eliminated both by tubular excretion and glomerular filtration. The elimination rate constants (Beta) for the major organs were as follows: muscle, 0.00343 min^-1; lung, 0.0310 min^-1; fat, 0.0394 min^-1; and kidney, 0.0213 min^-1, which compared favorably with the elimination rate constant found in plasma (0.0320 min^-1). These values were found to be significantly similar at the level of P < 0.005 in muscle, spleen and fat, and at a level of P < 0.025 in lung tissue. The data indicates that blood plasma would be a satisfactory body fluid for estimating this drug in tissue.     

免疫应激对仔猪理想氨基酸平衡模式影响的研究

采用氨基酸部分扣除法研究了人工诱导免疫应激条件下仔猪可消化赖氨酸（DLys）、蛋氨酸（DMet）、色氨酸（DTrp），苏氨酸（DThr）之间的平衡比例。结果表明：仔猪处于正常和免疫应激条件下的理想氨基酸模式存在差异，应激条件下，以可消化氨基酸为基础的这4种氨基酸的平衡比例为DLys100、DMet27、DTrp29、DThr59；正常条件下为DLys100、DMet30、DTrp21、DThr61。     

甘肃天祝高寒地区5种灌木中酚类物质含量的研究

对甘肃天祝金强河高寒地区5种灌木中的酚类物质含量进行了测定和比较分析。结果表明,不同的灌木品种其酚类物质的含量不同。藏沙棘总酚,单宁和缩合单宁的干物质含量均高于其他灌木,分别高达69.67,63.34和42.45 g/kg,而其简单酚的干物质含量最低,仅为4.27 g/kg。窄叶鲜卑木的酚类物质含量较低,与其他灌木相比差异极显著(P<0.01)。相关性分析表明,单宁和简单酚含量呈显著的正相关关系(r=0.94,P<0.01),与缩合单宁的相关系数为r=0.82(P<0.05),而简单酚与缩合单宁含量呈不显著的负相关关系。     

瘤胃微生物总DNA快速提取法研究

本文介绍了一种简便快速地提取瘤胃微生物细胞总DNA的方法,该法是对提取植物的CTAB法进行改进而成。与经典反复冻融 SDS/蛋白酶K裂解法相比,该法可在数小时内高效地提取瘤胃内容物总DNA,经琼脂糖凝胶电泳对所提取瘤胃微生物总DNA进行检测,证明所获得的瘤胃总DNA符合分子生物学操作要求。     

中链脂肪酸对体外发酵甲烷产量的影响

利用人工瘤胃体外产气法研究不同精粗比(0:1和1:1)日粮类型时中链脂肪酸对甲烷产量的影响。结果显示,体外培养24h,添加脂肪酸对甲烷产量的抑制作用不受日粮类型的影响(P>0.05);与不添加酸的对照相比,添加50mg未酯化月桂酸(C12:0)及月桂酸和肉豆蔻酸(C14:0)以3:2的比例组成的混合物(50mg)可分别抑制甲烷产量的22.2%(P<0.01)和11.8%(P<0.05);添加50 mg未酯化C14:0使甲烷产量降低3.4%(P>0.05);不同日粮类型上饲料产气量、瘤胃液pH值和氨氮浓度差异显著(P<0.01)。     

猪肌肉生长抑制素基因的克隆及原核表达

本试验旨在通过基因工程方法获得重组肌肉生长抑制素蛋白。根据基因库肌肉生长抑制素基因序列设计合成特异性引物,引物两端分别加上EcoRⅠ和SalⅠ酶切位点及保护碱基,提取汉普夏猪的骨骼肌总RNA,用RT-PCR方法扩增肌肉生长抑制素全长基因,并将其克隆到pMD18-T载体上,测序后EcoRⅠ和SalⅠ双酶切,克隆到pET-30a( )中,构建原核表达载体pET-30a-M,将重组表达质粒转化至E.coliBL21(DE3)中,诱导表达。结果表明,成功扩增出肌肉生长抑制素全长基因;克隆载体经过DNA序列测定,所得基因与国外报道的完全一致;成功构建原核表达载体pET-30a-M;经IPTG诱导,表达出了6×His-M融合蛋白,用组氨酸标签抗体做Western印记证明产物大约48 ku,与预期大小相符,肌肉生长抑制素蛋白在大肠杆菌中成功的进行了表达。     

泥胡菜水提物的体外抗菌作用试验

采用试管预试法和圆形滤纸层析法对泥胡菜的化学成分进行分析,结果表明,泥胡菜含有生物碱、有机酸、蛋白质、多肽、氨基酸、酚性成分、鞣质、糖类等化学成分;用纸片法和试管法对泥胡菜水提取液进行体外抗菌作用试验,结果表明,泥胡菜水提取液对金黄色葡萄球菌、巴氏杆菌、链球菌、沙门菌、大肠埃希菌都有较强的抗菌作用.抑菌圈直径分别为19.66 mm±0.53 mm、13.45 mm±0.21 mm、15.84 mm±1.23 mm、12.78 mm±0.34 mm、12.43 mm±0.52 mm;泥胡菜水提取液对金黄色葡萄球菌、巴氏杆菌、链球菌、沙门菌、大肠埃希菌的最低抑菌浓度(MIC)分别为0.063、0.125、0.25、0.125、0.25 g/mL.最低杀菌浓度(MBC)分别为0.063、0.25、0.5、0.125、0.25 g/mL.     

五龙鹅早期血浆总蛋白质消长规律与成分研究

本试验选用五龙鹅蛋用系与快长系各150只进行网床育肥试验,测定血浆总蛋白质含量,并进行PAGE电泳。结果显示:初生雏鹅血浆总蛋白质含量较高,随着日龄(1~90 d)增加呈先下降后升高趋势,以对数函数和抛物线函数分段拟合效果较佳,R2为0.9445、0.9568;血浆总蛋白质含量在性别间差异不显著,品系间差异显著。PAGE电泳结果表明:血浆中蛋白质种类在品系、性别间没有差异,随日龄的增加亦没有条带变化。清蛋白含量的变化是引起血浆总蛋白质含量变化的主要因素。     

Expression of TGF-β1 and Smad2/3 in kidney of STZ-induced diabetic nephropathy rats

AIM: To study the role of TGF-β/Smad pathway in the development of renal fibrosis in diabetic nephropathy.METHODS: Rats were induced to diabetic nephropathy by using tail intravenous injection of STZ.The expression of TGF-β₁, Smad2/3 protein and mRNA in kidney were examined at 2, 4, 8 and 16 weeks after STZ induction.CTGF, collagen-Ⅲ, PAI-1 mRNA expression in kidney at 16 weeks of STZ-induced diabetic nephropathy and normal rats were studied by RT-PCR.RESULTS: Weak TGF-β₁, Smad2/3 protein were detected in normal renal tissues while strong TGF-β₁, Smad2/3 staining were observed in renal tissues of diabetic nephropathy (0.057±0.030/0.223±0.040;0.017±0.010/0.153±0.010, respectively, P<0.05).The TGF-β₁, Smad2/3 protein expression were constantly high with the development of diabetic nephropathy and fibrosis (0.153±0.010, 0.122±0.050, 0.141±0.070 and 0.216±0.030 for 2, 4, 8 and 16 weeks, respectively).The TGF-β₁, Smad2 mRNA expression also increased with the development of diabetic nephropathy (2.86, 3.25 fold compared to control, respectively).The expression of TGF-β₁, Smad2, CTGF, collagen-Ⅲ and PAI-1 mRNA were significantly higher in kidney of 16 week diabetic nephropathy rats than that in normal ones (3.92, 2.95, 1.57, 1.95 and 1.97 folds compare to control, respectively, P<0.05).CONCLUSION: The results indicate that TGF-β₁/ Smad2 pathway activity might play an important role in pathophysiological process of diabetic nephropathy.It may be involved in diabetic renal fibrosis through up-regulation of CTGF and PAI-1 to promote extracellular matrix deposition.     

共轭亚油酸对五龙鹅生长发育和脂质代谢的影响

1日龄五龙鹅192只，随机分为4个处理，分别饲喂共轭亚油酸（CLA）水平为0．0、5．0、15．0和25．0g／kg的日粮，通过测定不同生长阶段的体增重（BWG）、采食量（FI）、料重比（F／G）、腹脂率（AFP），以及与脂质代谢有关血清生化指标，研究不同水平CLA日粮对五龙鹅生长发育和脂质代谢的影响。结果表明：在日粮中分别添加5．0g／kg和15．0g／kgCLA，对五龙鹅BWG无显著影响（P〉0．05），能够显著降低FI和F／G（P〈0．05）；显著降低AFP和血清甘油三酯（TG）、胆固醇（TC）、极低密度脂蛋白（VLDL）含量（P〈0．05或P〈0．01），增加了血清高密度脂蛋白胆固醇（HDL-C）含量和高、低密度脂蛋白胆固醇之比（HDL-C／LDL-C）（P〈0．05）。日粮中添加25．0g／kgCLA，极显著地降低了FI和AFP（P〈0．01），对血清TG、TC、HDL-C、VLDL含量和HDL-C／LDL-C的影响差异不显著（P〉0．05）。适宜添加CLA对五龙鹅的生长发育和脂质代谢具有很好的促进和调节作用，即在五龙鹅的整个生长期内，CLA添加量不高于15．0g／kg时，不但能在不影响BWG的前提下提高饲料利用率，而且能够通过降低脂肪沉积和调节脂质代谢起到预防动脉粥样硬化的作用；但过多添加CLA（25．0g／kg）会使五龙鹅的生长发育受到抑制。