Ali, Khalid Eltom

2018-05-14T10:11:36Z

2018-05-14T10:11:36Z

1969

Plasma iron in laying hens is about five times higher than in non-laying birds and mammals. About half the total iron has properties different from those of tx'ansferrin-bound iron. It has been suggested by some workers that the non-transferrin iron is bound to conalbumin.

In the present work studies were made on plasma containing the native non-radioactive iron and on plasma to which 59 radioactive iron Fe) had been added in vivo or in vitro. Several types of separation techniques (gel filtration on Sephadex, adsorption on magnesium carbonate, chromatography on DEAE-cellulose) were employed for the fractionation of the plasma and the identification of the iron-binding components. Studies were also made on cockerels where a plasma iron picture similar to that found normally in laying hens could be induced by the administration of oestrogen. The results of all these experiments indicate that the non-transferrin iron is associated with phosphoprotein and 59 not with conalbumin, although an attempt to isolate Pe-labelled phosphoprotein quantitatively was only partially successful. The findings of other workers who have used, various electrophoretic techniques are discussed and found to be explicable on the basis of this hypothesis.

Specific radioactivity measurements made after the CO incubation of J Pe-transferrin (in normal cockerel plasma) with the phosphoprotein iron in plasma from laying hens show that V there is no exchange between the two iron fractions in vitro. Similar measurements made after the intravenous injection of co Fe-transferrin show that in laying hens and oestrogen-treated cockerels transferrin iron serves as a precursor of the phosphoprotein iron. Thus the phosphoprotein iron is presumably derived from transferrin iron in vivo by some process other than simple transfer in the plasma. It is proposed that the iron is taken from transferrin by the newly synthesized phosphoprotein which is leaving the liver cells to be released in the blood plasma, and that the possible funotion of the phosphoprotein iron is to serve as a source of iron for the eggs.

http://hdl.handle.net/1842/29671

The University of Edinburgh

Annexe Thesis Digitisation Project 2018 Block 18

Already catalogued

Some aspects of iron metabolism in birds

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Doctoral

PhD Doctor of Philosophy