Shennan D B, McNeillie S A, Jamieson E A, Calvert D T
Hannah Research Institute, Ayr, UK.
Acta Physiol Scand. 1994 Aug;151(4):461-6. doi: 10.1111/j.1748-1716.1994.tb09768.x.
The transport of lysine by the lactating rat mammary gland has been examined to determine whether there is an interaction between cationic and neutral amino acids. Lysine uptake was time dependent and unaffected by replacing Na+ with choline. In the presence of Na+, lysine influx was inhibited by cationic amino acids (arginine, homoarginine, ornithine and lysine) and by a range of neutral amino acids (methionine, glutamine, leucine, phenylalanine, alanine, asparagine, alpha-aminoisobutyric acid (AIB), 2-aminobicyclo [2,2,1] heptane-2-carboxylic acid (BCH), proline and tryptophan). Leucine and glutamine also inhibited lysine influx in the absence of Na+ but phenylalanine and proline did not. Lysine efflux from mammary tissue was trans-accelerated by various cationic amino acids (lysine, arginine, homoarginine and ornithine). In addition, leucine and glutamine were capable of trans-stimulating lysine efflux in the presence and absence of Na+. It appears that cationic and neutral amino acids stimulated lysine efflux at a single locus.
为了确定阳离子氨基酸和中性氨基酸之间是否存在相互作用，研究人员对泌乳大鼠乳腺中赖氨酸的转运进行了检测。赖氨酸的摄取具有时间依赖性，并且用胆碱替代Na+对其没有影响。在存在Na+的情况下，阳离子氨基酸（精氨酸、高精氨酸、鸟氨酸和赖氨酸）以及一系列中性氨基酸（蛋氨酸、谷氨酰胺、亮氨酸、苯丙氨酸、丙氨酸、天冬酰胺、α-氨基异丁酸（AIB）、2-氨基双环[2,2,1]庚烷-2-羧酸（BCH）、脯氨酸和色氨酸）会抑制赖氨酸的流入。在不存在Na+的情况下，亮氨酸和谷氨酰胺也会抑制赖氨酸的流入，但苯丙氨酸和脯氨酸则不会。乳腺组织中赖氨酸的流出会被各种阳离子氨基酸（赖氨酸、精氨酸、高精氨酸和鸟氨酸）反式加速。此外，无论存在还是不存在Na+，亮氨酸和谷氨酰胺都能够反式刺激赖氨酸的流出。看来阳离子氨基酸和中性氨基酸在单一部位刺激了赖氨酸的流出。
