Acta Morphologica 14. (1966)
3-4. szám - Morphologia Normalis et Experimentalis - Krompecher St.–László M. B.–Ladányi P.: Some Metabolic Changes during the Chick’s Ontogenesis
Acta Morphologica Academiae Scientiarum Hungaricae Tomus 14 (3—4), pp. 267 — 268 (1966) Institute of Anatomy, Histology and Embryology (Director: St. Krompecher) University Medical School, Debrecen SOME METABOLIC CHANGES DURING THE CHICK’S ONTOGENESIS A PRELIMINARY REPORT St. Krompecher, M. B. László and P. Ladányi (Received January 26, 1966) According to earlier investigations there seems to be a correlation between the intensity of oxybiotic metabolism and the content of tissue mucopolysaccharides (hexosamines). Experimental [1, 3, 9], pathological [4, 5] and phylogenetical [6, 7] observations demonstrate that tissues with high metabolic activity show a significantly high cytochrome oxidase activity whereas their mucopolysaccharide content is relatively slight. On the other hand, bradytrophic tissues (umbilical cord, cartilage, vitreous body, tissues of primitive animals, etc.) beside a slight (or no) cytochrome oxidase activity have sometimes an extremely high mucopolysaccharide content [5]. Mainly on the analogy of our phylogenetical observations [6, 7] we have investigated the correlation between cytochrome oxidase activity and tissular hexosamine content during ontogenesis in the chick. Hexosamine was determined according to Boas [2] and cytochrome oxidase according to Pearl et al. [8]. Heart, liver, kidney, muscle and brain tissues were studied; in each of them 3 or 4 determinations were made for cytochrome oxidase and 5 for hexosamine. In order to characterize the various developmental stages, the means of the five kinds of tissue are shown in Fig. 1. Cytochrome oxidase activity was increasing from the 11-day old embryonic to the grown-up stage. At the same time the hexosamine level decreased. Accordingly, embryonic metabolism is characterized by a high mucopolysaccharide content and low cytochrome oxidase activity, whereas postembryonic metabolism is characterized by high cytochrome oxidase activity and low mucopolysaccharide (hexosamine) content. In this manner the metabolic conditions of embryonic life are similar to those of the primitive animal having an undeveloped cardiovascular system. Thus, this type of metabolism (mucopolysaccharide-type metabolism), characterized by a low cytochrome oxidase activity and a high mucopolysaccharide * * The material of this paper has been presented at the VII. International Embryolo”;ical Conference, London 1965. Acta Morphologien Academiae Scientiarum Hungaricae 14. I966