Previous work from our laboratory has demonstrated that the inner medullary collecting duct (IMCD) expresses a large amount of nitric oxide synthase (NOS) activity. The present study was designed to characterize the transport of NOS substrate, L-arginine, in a suspension of bulk-isolated IMCD cells from the Sprague-Dawley rat kidney. Biochemical transport studies demonstrated an L-arginine tran...

In the present study, we examined the role in hematopoiesis of cationic amino acid transporter 1 (CAT1), which transports L-arginine, L-lysine, L-ornithine, and L-histidine. The expression level of human CAT1 (hCAT1) mRNA in mononuclear cells (MNCs) fractionated according to lineage-selective markers was examined by reverse transcriptase-polymerase chain reaction. The expression of CAT1 in glyc...

Fetal growth and development are dependent on the delivery of amino acids from maternal amino acid pools to the fetal blood. This is accomplished via transfer across the apical and basal plasma membrane of the placental syncytiotrophoblast. The aim of this study was to determine whether inhibition of system A (amino acid transporter) was associated with a decrease in fetal weight in the rat. Sy...

Information regarding cationic amino acid transport systems in thyroid is limited to Northern blot detection of y(+)LAT1 mRNA in the mouse. This study investigated cationic amino acid transport in PC cell line clone 3 (PC Cl3 cells), a thyroid follicular cell line derived from a normal Fisher rat retaining many features of normal differentiated follicular thyroid cells. We provide evidence that...

While transport processes for amino acids and glucose have long been known to be expressed in the luminal and abluminal membranes of the endothelium comprising the blood-brain and blood-retinal barriers, it is only within the last decades that endothelial and smooth muscle cells derived from peripheral vascular beds have been recognized to rapidly transport and metabolize these nutrients. This ...

The structure and function of the four cationic amino acid transporters identified in animal cells are discussed. The systems differ in specificity, cation dependence, and physiological role. One of them, system y+, is selective for cationic amino acids, whereas the others (B[0,+], b[0,+], and y+ L) also accept neutral amino acids. In recent years, cDNA clones related to these activities have b...

There is an increasing appreciation that amino acids can act as signaling molecules in the regulation of cellular processes through modulation of intracellular cell signaling pathways. In culture, embryonic stem (ES) cells can be differentiated to a second, pluripotent cell population, early primitive ectoderm-like cells in response to biological activities within the conditioned medium MEDII. ...