Biomaterial Database

2-Chloroadenosine, a permeant for the nucleoside transporter. 1985

S M Jarvis, and B W Martin, and A S Ng

Human erythrocytes were shown to possess a saturable uptake mechanism for 2-chloroadenosine (apparent Km 23 microM, 22 degrees). Uptake by this route was inhibited by nitrobenzylthioinosine, uridine and adenosine, but adenine had no effect. In addition, uridine caused the countertransport of 2-chloroadenosine and vice versa. 2-Chloroadenosine was also shown to be an apparent competitive inhibitor of uridine influx (apparent Ki value of 33 microM) and high-affinity nitrobenzylthioinosine binding (apparent Ki 0.18 mM). The apparent Ki value for inhibition of uridine influx was close to the apparent Km value for 2-chloroadenosine uptake. Previous studies [Jarvis et al., Biochem. J. 208, 83 (1982)] have demonstrated that dog erythrocytes do not possess a saturable transport system for uridine and adenosine. Similarly, in the present study, the entry of 2-chloroadenosine into dog erythrocytes was slow and linear with concentration. Nitrobenzylthioinosine (NBMPR) had no effect on the uptake of 2-chloroadenosine into dog erythrocytes. These results demonstrate that 2-chloroadenosine enters human erythrocytes by the same nucleoside carrier as other nucleosides. It is suggested from these data that the previous explanation that the inability of nucleoside transport inhibitors to potentiate the pharmacological effects of 2-chloroadenosine was due to the failure of the nucleoside carrier to accept 2-chloroadenosine as a permeant may have to be reassessed.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D001798	Blood Proteins	Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.	Blood Protein,Plasma Protein,Plasma Proteins,Serum Protein,Serum Proteins,Protein, Blood,Protein, Plasma,Protein, Serum,Proteins, Blood,Proteins, Plasma,Proteins, Serum
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000225	Adenine	A purine base and a fundamental unit of ADENINE NUCLEOTIDES.	Vitamin B 4,4, Vitamin B,B 4, Vitamin
D000241	Adenosine	A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.	Adenocard,Adenoscan
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic