The transport of blood iron in some mammals

Abstract

In a previous paper (1) we have studied the serum iron of six mammalia species and the findings suggested the continua- tion of the study on new aspects of the serun iron.

From Laurell’s studies (2) it is known that circulating iron is united to a fraction of globulin named siderophilin ortransferrin, whose concentration is expressed as the máximum amount of iron it is capable of binding, which varíes between 250-400 y % (total binding capacity or TBC).

Another valué of interest in defining the iron transport is the latent binding capacity which represents the amount of free circulating siderophilin, which is the difference between TBC and the serum iron. We related these last two valúes in the form of saturation coefficient (SC) which constitutes their difference expressed in percentage ; this figure appears to us more demostrative and manageable.

In the present paper we study the serum iron and the TBC of seven animal species and the human, following Ramsay’s technique (5, 6). From these values the corresponding satura­ tion coefficients are calculated. The different valúes obtained have been statistically elaborated and the significance of the existing differences between the average valúes analized.

On table I the average values obtained can be observed, grouped in specie and sex, and the average valúes and their errors, the extreme valúes, and the typical deviations are also expressed.

The serum iron valúes here obtained show a 30-50 % reduction in respect to those indicated before (1), as a conse- quence of the aplication of Ramsay’s new technique (5); we explain this difference by the elimination of serum pigments (specially bilirubin) by the addition of chloroform in the new method.

We did not find sexual níƒor specific differences statistically significative between the different species studied. In thecomparison between the species, the valúes of both sexes have been grouped, as there were no differences between them. The Ovis arios specie has been eliminated from the comparison on account of not being totally homogenous in age. As for the iron serum valúes, we have been able to verify our previous conclusions.

These wide fluctuations in the serum iron valúes on the different species, is in contrast with the fact that the corresponding TBC shows highly significative differences. There do not exist sexual differences respecting the valúes, ne- vertheless, specific differences appear which show a statistical significance -(table II), from which the porcine species stands out with an average of 476.8 y %.

The saturation coefficient (SC) do not show sexual diffe­rences either, and their valúes within the different species varybetween 30-40 %, except on the porcine species on which it is 23.1 % and whose differences with the remaining are the only ones statistically significative (table III).

For the time being we do not know the physiological signi­ ficance of the high TBC and the low SC valúes on the pigs,which stand out clearly from the remaining species studied.