The Periodic Acid-Schiff Reaction of Blood Cells and the Appearance of Pigmented Leucocytes in Various Vertebrates

The 22nd Report of the Histochemical Study of Peroxidase

Abstract

This comparative study was made on 34 different species of vertebrates,216 cases in all, from monkey to urodela.
The periodic acid-S chiff (PAS) reaction of blood cells, with and without the use of saliva, was examined, some in more detail than others. The presence or existence of the pigmented leucocytes in the streaming blood was simultaneously tested from the standpoint of comparative hematology.
As to the PAS reaction intensities of neutrophil leucocytes, the following three groups could be classified: firstly amphibian group, the strongest; secondly reptilian group, the moderate; and thirdly avian group, the weakest reactive group. The mammals generally indicated a wide variation ranging from the strongest group to the weakest group. Among these, however, the neutrophils of horse, toad and tadpole indicated a particularly intense reaction. The PAS reaction of human neutrophils was weaker than these, but stronger than the other mammalian, reptilian or avian groups. This relationship is somewhat different from the results of the peroxidase reaction where human neutrophils consistently indicated the strongest reaction in all kinds of vertebrates. Generally speaking, it was also noticed that there was a certain parallel in the glycogen and peroxidase reaction activities in the animal neutrophils, while not at all in the animal eosinophils.
The eosinophil leucocytes, whenever present, contained the PAS reactive substance in their intergranular or ground substance, agreeing with the localization of the alkaline phosphatase reaction. The PAS reactive substance of them was hardly digested by saliva as in the avian pseudoeosinophil leucocytes. Regarding the reaction intensities of the eosinophils, particular racial variations, namely, significant phylogenetical relations could not be found.
It is worthy of note that the glycogen content in the neutrophils of the cold-blooded vertebrates did not decrease even at the end of hibernation. Again it was interesting to find that the snake's blood platelets contained the largest clump of the PAS reactive substance, and that the rodents except guinea pig were generally characterized by the relatively weak PAS-reaction of the neutrophils. In short, as to the periodic acid-Schiff reaction, a continuous evolution of blood cells could not be found, and profound gap in the phylogenetical relationship was distinctly shown between mammalia and ayes.
The pigmented leucocytes in the streaming blood could be seen in the cold-blooded animals, while not in the warm-blooded animals. They were rarely found in lizards, frogs, toads, newts and salamanders, while frequently found in tadpoles. The pigmented leucocytes, if present, generally came to below 0.5 per cent of the whole leucocytes in each animal. They possessed the character of monocytes or polymorphonuclears, which phagocytosed a certain amount of the pigment granules, and indicated negative peroxidase reaction.