An Early Response of the Morphologically Recognizable Erythroid Precursors to Bleeding

Hanna, Ismail R. A.

doi:10.1111/j.1365-2184.1968.tb00950.x

Cited by 6 publications

(5 citation statements)

References 10 publications

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“…The increased proliferation in nucleated red cells was followed later by an increase in red cell output. The red cell mass measured 3 days after the completion of the 5 day stimulation period was increased by 15.47 ml/kg body weight. Changes in reticulocyte concentration and in red cell size and hemoglobin content occurring with stimulation are shown in Table III.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, in normal animals erythropoietin has the opportunity to act on both undifferentiated erythroid precursors and cells maturing at the time of stimulation. If the number of mitotic divisions during the maturation sequence were increased (15), there should be an increase in the number of nucleated red cells beyond that derived from precursor input. The first 24 hr is critical because changes in terminal mitoses cannot be detected after a new maturation pattern is established.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

On the in vivo action of erythropoietin: a quantitative analysis

Papayannopoulou¹,

Finch²

1972

J. Clin. Invest.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

On the in vivo action of erythropoietin: a quantitative analysis

Papayannopoulou¹,

Finch²

1972

J. Clin. Invest.

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“…The experiments described in this paper were all carried out when the erythroid system had reached a new steady state in response to the stress, and therefore they provide no information about the changes that take place during the period of adaptation to the stress. In a recent study on the effects of acute blood loss Hanna (1968) has shown that immediately after the onset of anaemia the transit tirne is not changed, but that the recognizable precursors do, in fact, undergo extra divisions during maturation. This implies that the cycle time is reduced very early after the onset of anaemia.…”

Section: Discussionmentioning

confidence: 99%

Cell Population Kinetics of the Erythroid System in the Rat. The Response to Protracted Anaemia and to Continuous γ‐Irradiation

Tarbutt

1969

Br J Haematol

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Summary: Estimates have been obtained of the parameters defining the cell population kinetics of the erythroid system in rats subjected to protracted anaemia and to continuous γ‐irradiation at 43 rad/day. The inflow of cells to the proerythroblast compartment and the outflow of erythrocytes to the circulation have been measured by 55Fe autoradiography. In the anaemic rats, the ratio of the outflow to the inflow is normal, indicating that the precursors undergo the normal number of divisions during maturation from proerythroblast to erythrocyte. In the continuously irradiated rats, the outflow is normal but the inflow is decreased by a factor in the range 2–4, so that the ratio of the outflow to the inflow is increased by this factor, and the cells undergo more divisions than normal during maturation. The cell proliferation parameters of the various maturation stages of the erythroid system have been determined in anaemic rats, using 3H‐TdR autoradiography. The number of divisions undergone during maturation through each stage is normal, but the maturation times and cycle times are considerably reduced. Less information is available on the proliferation parameters in the continuously irradiated rats, but the 55Fe experiments indicate that the transit times of the proerythroblasts and of the non‐dividing stages of the system are increased in response to this stress.

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“…This occurs by the breakdown of RNA to low molecular weight products (76,79). During erythropoietic stress, erythroid development is characterized by a decreased marrow or spleen transit time (29,31,(80)(81)(82), which may be the result of shortened cell-cycle times (29,81,83) or of a reduction in the number of mitotic divisions (31,(52)(53)(54) or both (84). The loss of RNA might therefore occur during a shorter time period than in normal erythropoiesis.…”

Section: Effect Of Friend Virus Infectionmentioning

confidence: 99%

Nucleoside deaminase: an enzymatic marker for stress erythropoiesis in the mouse

Rothman¹,

Zanjani²,

Gordon³

et al. 1970

J. Clin. Invest.

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A B S T R A C T The level of nucleoside deaminase was determined in extracts of mouse tissues obtained during a period of accelerated erythropoiesis induced by hypoxia, hemorrhage, or the injection of phenylhydrazine. Under these conditions a striking (10-to 100-fold) elevation of the enzyme activity occurred in the spleen. Similar results were obtained with the injection of purified erythropoietin. In control animals, only a trace of nucleoside deaminase activity was detected in the blood. During the reticulocyte response which followed erythropoietic stimulation, there was a sharp increase in the blood level of nucleoside deaminase, which rose up to 120 times that of control animals. By differential centrifugation, the enzyme was localized to the reticulocyte-rich fraction. Erythrocyte nucleoside deaminase remained elevated even after the reticulocyte count had fallen to normal in the phenylhydrazine-treated mice or to zero after the cessation of hypoxia. There was a very gradual decline in the enzyme activity in the blood which fell to the barely detectable control levels about 45 days after the initial reticulocyte response, a time period which corresponds to the survival of the mouse red blood cell. The persistence of high levels of nucleoside deaminase for the full life span of a generation of erythrocytes formed during stress, viewed in contrast to the virtual absence of the enzyme from normal erythrocytes of all ages, represents an enzymatic difference between the normal red blood cell and the cell produced under conditions of accelerated erythropoiesis.

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An Early Response of the Morphologically Recognizable Erythroid Precursors to Bleeding

Cited by 6 publications

References 10 publications

On the in vivo action of erythropoietin: a quantitative analysis

On the in vivo action of erythropoietin: a quantitative analysis

Cell Population Kinetics of the Erythroid System in the Rat. The Response to Protracted Anaemia and to Continuous γ‐Irradiation

Nucleoside deaminase: an enzymatic marker for stress erythropoiesis in the mouse

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