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87-4 RESPIRATION AND OXIDATION.
for example with the lecithins (Thunberg, Warberg and Meyerhof l
as well as in the oxidation of certain thio-compounds.2
Batelli and Stern 3
have made careful investigations as to the
occurrence of peroxidases in the animal organism. In order to eliminate
the action of catalases which are present in the tissues and which,
as shown by earlier investigators, decompose the hydrogen peroxide,
these experimenters used ethyl hydrogen peroxide, C2H5.O.O.H, on
which the catalases do not act. With ethyl hydrogen peroxide and
hydroidic acid nearly all animal tissues gave the peroxidase reaction,
wherein free iodine was formed. Scheunert, Grimmer and Andryewski 4
make use of the following solution as a reagent for peroxidases: 100 cc.
fresh tincture of guaiacum and 0.1 to 0.2 cc. 3 per cent H2O2 solution.
Blood does not give any blue coloration with this reagent, but in the pres-
ence of large quantities of H2O2 or other superoxide solutions (ethylhy-
drogen peroxide, oil of turpentine) it does give a blue coloration. With
this active tincture of guaiacum these experimenters were able to detect
peroxidases in the salivary glands, as well as the mucous membrane
of the stomach and intestine of certain varieties of animals. The liver
was always free from peroxidases. On the other hand, Batelli and Stern 5
also tested the ability of various tissues of acting upon formic acid in the
presence of H2O2 with the evolution of carbon dioxide. In later works
these experimenters claim that in all animal tissues there exists a substance
of an unknown nature, the pnein, which has the ability of bringing about
the respiration in all animal tissues. Pnein, which is soluble in water,
dializable and resistant to temperature, increases the so-called chief respira-
tion, which is connected with the life of the cells and which stops more
or less rapidly after the death of the animal. The so-called accessory
respiration continues quite a long time, after death, and this can continue
in the absence of cell elements and is of an enzymotic character. Thun-
berg 6
, who has constructed an apparatus for measuring the respiratory
exchange of gas in small organs and organisms (microrespirometer) finds
that the salts of certain organic acids (succinic acid, citric acid, malic
acid, fumaric acid) accelerate more or less the gas exchange in surviv-
ing frog’s muscles. In their last communication Batelli and Stern 7
differentiate between two kinds of oxidation catalysts: the oxidases
and the oxidones. The first to which, among others the tyrosinase, alcohol-
1
Skand. Arch. f. Physiol., 24, 90 (1911); Zeitschr. f. physiol. Chem., 85, 412 (1913).
2
Thunberg, Lunds Univ. Arsskr., N. F., 2, Bd. 9 (1913).
« Bioch. Zeitschr., 13, 44 (1908).
* Ibid., 53, 300 (1913).
*Ibid., 21, 487 (1910); 30, 172 (1910); 33, 315 (1911).
Skand. Arch. f. Physiol., 17, 23, 24, 25 (1911).
7
Bioch. Zeitschr., 46, 317, 343 (1912); Compt. rend., soc. biol., 74, 212 (1913).
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