Turnover of purine nucleotides in rabbit erythrocytes I. Studies in vivo

Mager, J.; Hershko, Avram; Zeitlin-Beck, Ruth; Shoshani, Tavassah; Razin, A.

doi:10.1016/0005-2787(67)90690-9

Cited by 49 publications

(15 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The rabbit erythrocyte is similar to the human cell in that it cannot synthesize adenine nucleotides de novo but does have effective salvage pathways that will allow it to use available adenine or adenosine to synthesize these nucleotides (26). Actually, the rabbit erythrocyte is more flexible than the human cell in that it can also use inosine for the synthesis of adenine nucleotides (27). It is interesting that a group of disorders exists in humans that is characterized by high ATP levels in erythrocytes.…”

Section: Discussionmentioning

confidence: 99%

Senescent erythrocytes: isolation of in vivo aged cells and their biochemical characteristics.

Suzuki

Dale

1988

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Rabbit erythrocytes were covalently labeled with biotin and then infused into the donor animial. Up to 60 days after infusion, the biotinylated cells were selectively isolated by their affinity for avidin. These aged erythrocytes, which are within 10 days of death, were analyzed for several biochemical parameters. The 2,3-bisphosphoglycerate and glutathione levels of these cells were constant with age; however, the adenosine 5'-triphosphate concentrations increased approximately 75% as the cells approached the end of their life span. The activities of several glycolytic enzymes did not change with age.The mechanisms of erythrocyte senescence are poorly understood (1). Clearly, erythrocytes have a well-defined life span; however, the study of the aging processes in these cells has been hindered by the inability to definitively isolate senescent erythrocytes. A myriad of publications have reported age-related differences in various biochemical parameters of erythrocytes (for a review, see ref. 1). However, the majority of these are based on the separation of cells over density gradients with the underlying assumption that the most dense fractions represent the old cells, an assumption that has been questioned (2,3).Two methods that are independent of the physical separation techniques outlined above have been reported for the isolation of senescent erythroctyes. Allison and Burn (4) transfused blood group 0 erythrocytes into normal blood group A individuals. At subsequent time points, the 0 cells were recovered after agglutination of the host A erythrocytes. Unfortunately, the technique was hindered by technical difficulties. More recently, Ganzoni et al. (5) Preparation of Young Erythrocyte Cohorts. In some experiments, young erythrocyte populations were used for biotinylation and replacement into donor rabbits. The advantage of using a young cohort of cells is that a larger percentage of the cells will still be circulating 50-60 days after replacement and therefore will allow recovery of greater numbers of senescent cells. Two procedures were used to produce young cell populations-phenylhydrazine treatment and repeated phlebotomy. Phenylhydrazine hydrochloride (25 mg) was subcutaneously injected into a rabbit on days 0, 2, and 3. On day 13, 50 ml of blood was collected in heparin for biotinylation. The reticulocyte count for these preparations averaged more than 50% on day 8. For the repeated phlebotomy procedure, 50-60 ml of blood was drawn from the rabbit on day 0, 2, and 4. The sample for biotinylation was taken on day 14. To protect against iron deficiency during repeated phlebotomy, each rabbit received 50 mg of iron-dextran intramuscularly on days -7, -5, -3, 0, 2, and 4. Preparation and Infusion of Biotinylated Erythrocytes.Rabbit erythrocytes were washed, labeled with ['4C]cyanate, treated with NHS-biotin, and infused into the donor rabbit exactly as described (7). The average level of biotinylation was approximately 25,000 biotin molecules per erythrocyte.Avidin-Coated Polystyrene Beads. The av...

show abstract

Section: Discussionmentioning

confidence: 99%

Senescent erythrocytes: isolation of in vivo aged cells and their biochemical characteristics.

Suzuki

Dale

1988

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…In addition, the precise measurement of individual oxypurines in both the plasma and red blood cells may provide additional insight into the purine metabolism in gout. Studies have demonstrated that the ery throcytes function as the carrier mechanism for purine bases [7,12,14], and that even the concentration of hypoxanthine affects uric acid transport in erythrocytes [13]. The existence of a partial hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) deficiency among certain gouty patients [9] and the report of utilization of phosphoribosylpyrophosphate with allopurinol treatment [2] are conditions that further affect blood con centration of oxypurines.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Measurement of Plasma and Erythrocyte Oxypurines

Hayashi¹,

Gillo²,

Turner³

et al. 1972

Gynecol Obstet Invest

View full text Add to dashboard Cite

The individual oxypurine concentrations in the plasma and erythrocytes were determined among normal male subjects and gouty patients with and without allopurinol medication. Oxypurine measurements in the gouty patients on various medications but not on allopurinol displayed near normal values. However, allopurinol therapy produced a highly significant increase in the intracellular concentration of hypoxanthine associated with an additional increase in uric acid content in the red blood cells. Such changes suggest that xanthine oxidase inhibitors may possibly complicate the management of pregnancy toxemias by altering blood levels of oxypurines.

show abstract

“…In other studies, erythrocytes were implicated as a vehicle for purine transport from the liver to peripheral tissues (25). The major purine released from rabbit erythrocytes has been identified as hypoxanthine (26,27), suggesting that this base may be the purine transferred to peripheral tissues by the erythrocyte. In addition, hypoxanthine has been shown to be rapidly and efficiently cleared from plasma by the liver and hepatic adenosine release has been shown to be proportional to the concentration of hypoxanthine perfusing the liver (24).…”

Section: Discussionmentioning

confidence: 99%

Regulation of de novo purine synthesis in human bone marrow mononuclear cells by hypoxanthine.

King¹,

Honeysett²,

Howell³

1983

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T In previous studies from this laboratory, human bone marrow hypoxanthine concentrations were found to average 7.1 MM, three times higher than plasma hypoxanthine concentrations measured simultaneously. To assess the significance of this finding, the relationship between hypoxanthine concentration and the rate of purine nucleotide synthesis by the de novo pathway was studied in normal human bone marrow mononuclear cells and in the human promyelocytic cell line, HL-60, in vitro. Utilizing a ['4C]formate incorporation technique, rates of total cellular de novo purine synthesis as well as rates of de novo adenine, de novo guanine, and thymine synthesis and incorporation into RNA and DNA were nmeasured as a function of hypoxanthine concentration. In normal human marrow cells, the rate of total de novo purine synthesis declined by 81%, while the rate of de novo adenine and de novo guanine synthesis and incorporation into macromolecules declined by 89 and 75%, respectively, when media hypoxanthine was increased from 0 to 10 uM. Similar results were seen in the HL-60 cell line. In contrast, rates of thymine synthesis and incorporation into DNA as well as overall rates of RNA and DNA synthesis did not change with varying media hypoxanthine concentrations. In addition, hypoxanthine salvage and incorporation into RNA and DNA was shown to progressively increase with increasing media hypoxanthine concentrations. These results indicate that physiologic concentrations of hypoxanthine are sufficient to regulate the rate of de novo purine synthesis in human bone marrow in vivo.

show abstract

Turnover of purine nucleotides in rabbit erythrocytes I. Studies in vivo

Cited by 49 publications

References 12 publications

Senescent erythrocytes: isolation of in vivo aged cells and their biochemical characteristics.

Senescent erythrocytes: isolation of in vivo aged cells and their biochemical characteristics.

Simultaneous Measurement of Plasma and Erythrocyte Oxypurines

Regulation of de novo purine synthesis in human bone marrow mononuclear cells by hypoxanthine.

Contact Info

Product

Resources

About