Enhancing Effect of Zinc on L-Histidine Transport in Rat Lung Microvascular Endothelial Cells

• Published in: Biological trace element research Vol. 142; no. 3; pp. 713 - 722
• Main Authors: Sakurai, Eiichi, Sakurai, Eiko, Ueda, Yukari, Yagi, Yasuyuki
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01-09-2011; Humana Press Inc; Springer Nature B.V
• Subjects: 2,4-dinitrophenol; Animals; Biochemistry; Biological Transport - drug effects; Biomedical and Life Sciences; Biotechnology; Cells, Cultured; endothelial cells; Endothelial Cells - drug effects; Endothelial Cells - metabolism; glutamic acid; histidine; Histidine - metabolism; Hydrogen-Ion Concentration; Life Sciences; Lungs; Male; Nutrition; Oncology; Rats; Rats, Wistar; Rodents; sodium; Trace elements; transporters; Zinc; Zinc - pharmacology; Zinc Sulfate - pharmacology; histidine transport; Rat lung microvascular endothelial cells; ZnSO; System-L transporter; System-N transporter
• ISSN: 0163-4984; 1559-0720
• DOI: 10.1007/s12011-010-8797-8

The aim of this study was to examine enhancing effect of L-histidine into cultured rat lung microvascular endothelial cells (LMECs), which constitute the gas–blood barrier. Uptake of L-histidine into LMECs markedly increased with the addition of ZnSO4 (0.1 mmol/L), and this enhanced uptake of L-histidine was drastically reduced in the presence of the Na+-independent system L substrate, 2-amino-2-norbornanecarboxylic acid (BCH). However, the uptake of L-histidine together with ZnSO4 was not reduced by the addition of metabolic inhibitor, 2,4-dinitrophenol, or sodium ion replacement. Moreover, the addition of the system N-substrate, L-glutamic acid γ-monohydroxamate did not significantly decrease the uptake of L-histidine with 143 mmol/L Na + + 1 mmol/L BCH. These results indicated that system-N transporter does not play a role in the uptake of L-histidine in the presence of ZnSO4, suggesting that only system-L transporter is involved in the uptake of L-histidine, although L-histidine in the absence of ZnSO4 was taken up by at least two pathways of Na+-dependent system-N and Na+-independent system-L processes into rat LMECs. The uptake of L-histidine into rat LMECs in the presence of ZnSO4 was also found to be unaffected by pH (5.0–7.4), indicating that uptake of L-histidine into LMECs by the addition of zinc may not be involved in the H+-coupled transporters.