生长猪小肠钠依赖型磷摄入特性的研究  

Stduy on Characteristics of Sodium-dependent Phosphate Intake in Small Intestine of Growing Pig

作　　者：孙杰[1] 张铁鹰[2] 陈志伟[1] 韩进诚[3] 刘志伟[4] 

机构地区：[1]山东理工大学生命科学学院,淄博255049 [2]中国农业科学院北京畜牧兽医研究所动物营养学国家重点实验室,北京100094 [3]西北农林科技大学动物科技学院,杨凌712100 [4]河北农业大学动物科技学院,保定071001

出　　处：《畜牧兽医学报》2008年第1期108-112,共5页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：“973”子项目(2004CB117501);国家自然科学基金(30671528)

摘　　要：选取6头体重接近的3月龄生长期大白猪,屠宰后刮下肠黏膜,提取3段小肠上皮细胞刷状缘膜囊泡(Brush-border membrane vesicles,BBMV)。在室温条件下,研究各段小肠BBMV磷的摄入量,pH和钠离子依赖性,并测定BBMV磷吸收动力学参数。结果表明,生长猪BBMV对磷的主动吸收和被动扩散在酸性pH下均受到抑制。钠离子水平影响BBMV磷的主动吸收。pH7.4条件下,测得钠依赖型磷转运系统Hill系数(napp)为2.07,即转运1个磷酸根,至少有2个钠离子与其协同转运。不同肠段BBMV磷的主动吸收并没有显著差异。pH7.4条件下,生长猪钠依赖型磷转运系统对磷的亲和力常数(Km)为(0.43±0.09)mmol/L。最大转运速度(Vmax)为(2.25±0.19)nmol/(mg蛋白.15 s)。Six 3-month-old growing Yorkshire pigs were killed to obtain mucosa,which used to prepare epithelium brush-border membrane vesicles（BBMV）.The dependence of Pi uptake on pH and sodium concentration were discussed and kinetics of Na^＋-dependent Pi uptake into BBMV of growing pig were estimated by the measurement of phosphate uptake into BBMV within 15 s at room temperature.Results showed that acid pH made a negative effect on both sodium-dependent phosphate uptake and passive diffusion.Phosphate uptake into BBMV was strongly dependent on sodium concentration.Hill coefficient（napp） of sodium-dependent phosphate cotransport system was 2.07,which indicated that at least two sodium ion was transported with each phosphate ion.The differences of Pi uptake into BBMV between different intestinal segments were not significant.On the condition of varying Pi concentration（0-2.0 mmol/L） and pH7.4,the Pi concentration that yielded half-maximal transport（apparent Km） estimated was（0.43±0.09）mmol/L in Yorkshire BBMV.The maximal phosphate uptake into BBMV was （2.25±0.19）nmol/（mg protein·15 s）.

关 键 词：生长猪 刷状缘膜囊泡 磷摄入 

分 类 号：S816.71[农业科学—饲料科学]