Introduction to physiological chemistry / by Meyer Bodansky.

  • Bodansky, Meyer, 1896-1941.
Date:
1934
Catalogue details

Licence: In copyright

Credit: Introduction to physiological chemistry / by Meyer Bodansky. Source: Wellcome Collection.

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    TABLE I Composition of Sera of Animals as Related to that of Sea Water* Species Na K Ca Mg Dogfish {Acanthias vulgaris) 100 4,6 2.7 2.5 Cod {Gadus callarias) 100 9.5 3.9 1.4 Pollock {Pallachinus virens) 100 4.3 3.1 1.5 Dog 100 6.9 2.5 0.8 Man 100 6.1 2.7 0.9 Lobster {Homarus americanus) 100 3.7 4.9 1.7 Horseshoe crab (Limulus polyphemus). . 100 5.6 4.1 11.2 Jellyfish {Aurelia)—tissue fluid 100 5.2 4.1 11.4 Ocean water 100 3.6 3.9 12.1 * After Macallum, Trans. Coll. Phys. of Philadelphia, 39, 289, 1917. noted that the proportion of calcium to sodium in sea water and in sera is nearly the same. The correspondence is not so close with potassium, but nearly so. On the other hand, there is considerable variation in the case of magnesium. Macallum and, somewhat earher, the German physiologist, Bunge, have suggested that the high content of sodium chloride in the blood of vertebrates may be an inheritance from our remote ancestors who lived in the sea. Supposing that these animals took to the land after the development of a closed circulatory system, it might follow that the composition of the sea, as it was at that time, has persisted in their blood to the present day. How, then, are we to account for the divergences in potassium and magnesium? It has been suggested that since the Cambrian period less potassium has been supplied to the sea than prior to that time, because so much of this element has been required by plant life, which has been more profuse since the Cambrian era. However, the magnesium content of the ocean and the proportion of magnesium to sodium have been steadily increas- ing since pre-Cambrian time, the concentration found at present in the higher animals corresponding presumably to the low magnesium content of the sea at the time the animals in question acquired a terrestrial habitat. The calcium content has been increasing but slowly, owing perhaps to the utilization of calcium in the building of corals and the bones and shells of other marine organisms. To sum up, it may be stated that the blood serum of mammals resembles, except for the difference in its magnesium content, diluted sea water of our own day. ^ ^ For further details the student is referred to A. B. Macallum, “The Paleo- chemistry of the Body Fluids and Tissues,” Physiol. Rev., 6, 316 (1926); see also F. W. Clarke, “The Data of Geochemistry,” 4th edition, U. S. Geol. Survey, Bull. 695.