Responsiveness of the Erythron to Variations of Oxygen Tension in the Chick Embryo and Young Chicken

Abstract

The reactivity of the chick embryo erythron to varying ambient oxygen concentrations was investigated. The hemoglobin (Hb) concentration, the hematocrit and red cell count were determined in embryos incubated in 40 % O2, air and 15 % O2. The age of the embryos varied between 9 and 19 days. The results indicated that embryos weighing less than 7 g and approximately less than 14 days old do not increase their Hb, hematocrit or erythrocyte count when exposed to 15 % O2. In embryos aged 16 days or over the 15 % O2 exerts a stimulatory effect: the Hb and hematocrit values exceed those found in the embryos incubated in 40 % O2. The mean corpuscular volume and the mean corpuscular Hb are not affected by differences in ambient oxygen concentrations. It is pointed out that the 15th day of incubation seems to represent a critical phase in chick embryo development—it is not only approximately the date when myeloid erythropoiesis begins to dominate, but also the date when, for instance, some polyamines begin to be synthetized and the hypophysis becomes functionally active.

The Gaseous Environment of the Chick Embryo in Relation to Its Development and Hatchability

“…Hematological (Macpherson and Deamer, 1964) and electrophoretic (Fraser, 1961) studies support Hall's findings on the appearance and progressive change in hemoglobin type during the 9-12 day period. In the chick embryo hematopoiesis is not stimulated by exposure to low 0 2 until after the 15 th day of incubation (Jalavisto et al, 1965). The concentrations of erythrocytes and hemoglobin increase throughout incubation; however, the 9-12 day period shows the greatest increment (Zorn and Dalton, 1937;Barnes and Jensen, 1959).…”

Hypoxic level and duration differentially affect embryonic organ system development of the chicken (Gallus gallus)

“…For example, Tintu et al (2007) reported that chicken embryos exposed to 15% O 2 throughout embryonic development showed elevated hematocrit (Hct) and depressed total body, liver, and heart weights, as well as lower arterial blood partial pressure of O 2 (P O2 ) levels. However, other studies reported no significant effects of hypoxia (~15% O 2 ) on hemoglobin (Hb; Jalavisto et al, 1965;Dzialowski et al, 2002). Similarly, heart relative weight in chronic hypoxic exposure has variously been reported to increase (Rouwet et al, 2002;Lindgren and Altimiras, 2009), remain unchanged (Altimiras and Phu, 2000), or decrease (Ruijtenbeek et al, 2000).…”

Hematological Indices of Turkey Embryos Incubated at High Altitude as Affected by Oxygen and Shell Permeability

“…Chick (Gallus domesticus) embryos developing at sea level respond to decreased partial pressures of oxygen by increasing RBC and Hb (Jalavisto et al, 1965;Ackerman, 1970;Tazawa et al, 1971;Baumann et al, 1983), increasing PCV (Jalavisto et al, 1965), and increasing MCV (Ackerman, 1970;Ackerman and Ramm, 1971). Blood vasculature is also increased by decreasing atmospheric pressure (Snyder et al, 1984).…”