Cellular response to the ribonuclease injection; a morphologic and cytochemical study

By the repeated injection of RNase into mice the histological, cytochemical and electronmicroscope observations of several tissues and the quantitative estimation of DNA contents per cell in liver have been conducted. The observations proved that the most marked changes occur in basophilia, ER (endoplasmic reticulum) and Palade's granules; the dissociation of the granules from ER and their agglomeration, and the final disappearance of the granules and ER. The increase of the granules in number surrounding the nucleus seen in liver cells and the appearance of the ring form ER in the pancreatic exocrine cells and its development from the nuclear membrane have been traced morphologically and these are comprehended as the regenerating picture of ER and granules from the nuclear outer membrane. DNA contents in liver cell increase in the early stage and decrease to the normal level in the later stage. The former is attributed to the cessation of mitosis by the damage of cell center without interference on DNA synthesis and the latter to the disappearance of the cells of tetraproidy by degeneration.