Biochemical changes during reticulocyte maturation in culture. A comparison of genetically different sheep erythrocytes

Abstract

A simple culture technique was used to follow sheep reticulocyte maturation. Cells remained in good condition without lysis for at least 7 days and maintained normal intracellular ATP concentrations. Amino acid and nucleoside transport were measured during maturation together with changes in reduced glutathione (GSH), amino acid, K+ and Na+ concentrations. Reticulocytes of the genetic types high-K+ and low-K+, high-GSH and low-GSH; nucleoside-permeable and nucleoside-impermeable were indistinguishable both in transport properties and cellular constituents. Cell maturation was associated with marked decreases in L-alanine transport (Na+-dependent and independent), uridine transport and GSH and K+ concentrations. Typical mature-cell levels for all parameters were reached within the culture period, during which time predicted differences between cells of different genotypes became apparent. Loss of amino acid-transport activity from low-GSH cells was accompanied by an increase in intracellular ornithine and lysine concentrations. The rates at which different parameters changed during culture were compared.

Nucleoside translocation in sheep reticulocytes and fetal erythrocytes: a proposed model for the nucleoside transporter

“…However, the loss of transport and inhibitor binding activity was faster than the apparent reticulocyte maturation rate as judged by the loss of reticulin, suggesting that different biochemical parameters have different regression schedules (see also Tucker & Young, 1980).…”

“…Sources of other reagents used in the present study are detailed elsewhere (Tucker & Young, 1980;Jarvis et al 1982). …”

“…A common characteristic of the cation and amino acid transport phenotypes described above is that they are not distinguishable from each other at the reticulocyte stage of development (Tucker & Ellory, 1971;Tucker & Kilgour, 1973;Tucker & Young, 1980;Tucker, Young & Crowley, 1981). Reticulocytes also possess higher over-all transport rates than are ever found in mature erythrocytes.…”

Volume-sensitive taurine transport in fish erythrocytes

“…Physiologically, erythrocyte amino-acid transport has been shown to be important for the provision of amino-acid precursors for intracellular glutathione biosynthesis [15,17,20,33,39,40,48,57,60,61]. Erythrocyte amino-acid transporters also function as efflux routes for amino acids produced by protein degradation during reticulocyte maturation and perhaps also by hydrolysis of small peptides entering the cell from the plasma [18,[34][35][36]47]. Amino-acid transport across the erythrocyte plasma membrane is required for the development of the intracellular stages of mammalian and avian malarial parasites [27,44], and there is some evidence that erythrocytes may participate in interorgan transport of amino acids [8].…”

Heterogeneity of amino acid transport in horse erythrocytes: a detailed kinetic analysis of inherited transport variation.

“…In addition, the erythrocyte band 3 anion-exchange transporter has a significant affinity for glycine and some other amino acids Ellory et al 1981 b). Physiologically, erythrocyte amino acid transporters provide the amino acid precursors (L-cysteine, L-glutamate, glycine) for intracellular glutathione (GSH) biosynthesis (Young et al 1975(Young et al ,1976Young, Tucker & Kilgour, 1982; Maede, Inaba & Taniguchi, 1983;Inaba & Maede, 1984) and may also participate in the efflux of amino acids produced by protein degradation during reticulocyte maturation (Tucker & Young, 1980). It has also been suggested that amino acid transporters are responsible for the efflux of intracellular amino acids arising from erythrocyte hydrolysis of plasma peptides (King, York, Chapman & Kuchel, 1983;King & Kuchel, 1984Vandenberg, King & Kuchel, 1985).…”