Participation of NH4+ in total ammonia absorption across the rumen epithelium of sheep (Ovis aries)
Participation of NH4+ in total ammonia absorption across the rumen epithelium of sheep (Ovis aries)
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DOI：
10.1016/0300-9629(96)00012-6
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发表时间：
1996-08-01
期刊：
影响因子：
--
通讯作者：
Kemkowski, J
中科院分区：
文献类型：
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作者：
Bodeker, D;Kemkowski, J
1.体外实验研究了NH4+在绵羊瘤胃壁总氨转运中的作用。2.在Ussing小室中，在粘膜侧孵育液中加入NH_4~+或K~+可诱发正短路电流(I-SC)。Ba2+可阻断K~+诱导的Ise，但不能阻断NH~(4+)诱导的I-SC，奎尼丁可阻断K~+或NH~(4+)诱导的I-SC。4.当孵育液中含有奎尼丁时，氨跨上皮通量显著降低。5.钳制跨上皮电势差至-25 mV(浆膜侧极性)时，从粘膜到浆膜侧的氨通量显著大于电位差为+25 mV时测得的氨通量。6.推测NH4+参与了氨跨瘤胃上皮的转运，很可能是通过K+转运系统。
1. Participation of NH4+ in total ammonia transport across sheep rumen wall was studied in vitro. 2. In Ussing-type chambers addition of NH4+ or K+ to the incubation solution on the mucosal side of the epithelium evoked positive short circuit currents (I-SC) 3. The K+ induced Ise but not the NH4+ induced I-SC could be blocked by Ba2+ whereas both, K+ or NH4+ induced I-SC were blocked by quinidine. 4. Transepithelial fluxes of ammonia were significantly reduced when quinidine was present in the incubation solution. 5. When the transepithelial potential difference was clamped to -25 mV (polarity on the serosal side) ammonia fluxes from the mucosal to the serosal side were significantly larger than fluxes of ammonia measured at a potential difference of +25 mV. 6. It is suggested that NH4+ takes part in ammonia transport across the rumen epithelium, most probably by using a K+-transport system.