Abstract
The hearts of new-born rats (2-day-old, Wistar strain) were cultured using by Harary and Farley's method.
The re-organization of cultured cardiac cell was studied by phase contrast microscopy and by scanning and transmission electron microscopy. Cultured cardiac cells were stained with the PAS-reaction and stained for acid phosphatase activity. Differenciation of the general working cardiac cell and the conduction system cell was histochemically examined.
The results are as follows :
1) The round or polygonal cells with many microvilli on their surface were cardiac cells. The cells were connected with adjacent ones by long cytoplasmic extensions. On the third day of culture, cell clusters organized with single cells were formed and developed into network structure on the eighth day of culture.
2) In view of their reaction to saliva, PAS-positive granules were considered to be glycogen ones in cultured cardiac cells. PAS-positive cells were of two kinds; strongly or slightly positive one. Strongly PAS-positive cells were large and polygonal and had high acid phosphatase activity. This kind of cells were mainly cultured from the free wall of the left ventricle of new-born rats and were morphologically identified as Purkinje cells. The triangular cells with clear zones, stained positively with the PAS reagent, had also high acid phosphatase activity. This kinds of cells was obtained from the atrioventricular node. On the other hand, the round PAS-positive cells with low acid phosphatase activity were considered to be general working cells. The spindle-shaped cells with few PAS-positive granules and few or no glycogen granules were endotherial cells.3) Histochemically, the cells with high acid phosphatase activity were well-stained with the PAS reagent. Therefore, between these cultured cardiac cells the conduction system cells are presumed to have higher anaerobic glycolytic activity than the general working cells.
