Histochemical studies of adenosine triphosphatase activity of liver cells exposed to ribonuclease.

It has been revealed that ribonuclease (RNase) can penetrate into living cells and inhibits amino acid incorporation into proteins resulting in the suppreion of protein synthesis and growth of living cells. BHIDE, BRACHET, KAUFMAN and DAs have proven that the RNase penetrates into onion root-tip cells and induces a number of mitotic abnormalities. KIMOTO and others also have revealed that RNase injection into mice results in the reduction of cytoplasmic basophilia with the morphologic change of endoplasmic reticulum and the disturbances in DNA synthesis as demonstrated histochemically on pancreatic exocrine cells and liver cells. But there is little information so far on the mechanisms of penetration of RNase into living cells. PILLERI and SCHUMAKER4 in Brachet’s laboratory have demonstrated the uptake of RNase by pinocytosis in amoebae and cancer cells. This may suggest the penetration of RNase through the membrane of the endoplasmic reticulum in the cells whose RNase contents are low5, however it is reasonablly supposed that some phosphatase may be concerned with the permeability of RNase. ∗PMID: 14032743 [PubMed indexed for MEDLINE] Copyright c ©OKAYAMA UNIVERSITY MEDICAL SCHOOL Acta Med. Okayama 16, 29-32 (1962) HISTOCHEMICAL STUDIES OF ADENOSINE TRIPHOSPHATASE ACTIVITY OF LIVER CELLS EXPOSED TO RIBONUCLEASE Tetsuo KIMOTO and Kenji HAYASHI Department of Pathology, Okayama University Medical School, Okayama (Director: Prof. S. Seno) Received for publication, December 18, 1961 It has been revealed that ribonuclease (RNase) can penetrate into living cells and inhibits amino acid incorporation into proteins resulting in the suppression of protein synthesis and growth of living cells. BRIDE, BRACRETt, KAUFMAN and DAs have proven that the RNase penetrates into onion root-tip cells and induces a number of mitotic abnormalities. KIMOTO and others also have revealed that RNase injection into mice results in the reduction of cytoplasmic basophilia with the morphologic change of endoplasmic reticulum and the disturbances in DNA synthesis as demonstrated histochemically on pancreatic exocrine cells and liver cells. But there is little information so far on the mechanisms of penetration of RNase into living cells. PILLERIs and SCRUMAKER' in Brachet's laboratory have demonstrated the uptake of RNase by pinocytosis in amoebae and cancer cells. This may suggest the penetration of RNase through the membrane of the endoplasmic reticulum in'the cells whose RNase contents are low, however it is reasonablly supposed that some phosphatase may be concerned with the permeability of RNase. In the present work, an attempt has been made to study the histochemically demonstrable adenosine triphosphatase activity (ATPase) of mouse liver cells exposed to RNase in vitro, which may be correlated with permeability of RNase. The method used for the demonstration of ATPase was the one devised by WACRSTEIN and MEISEL but slightly modified by SENO and TOGAWA• But it has been recently claimed by FREIMAN that the reaction may be mainly of polyphosphatase. Small pieces of fresh liver tissue of C58 mice, about 3 mm. in size, were put in the phosphate buffer, pH 7.4, containing RNase, 10mg/dl, and incubated at 37 QC for 60 minutes. After incubation tissues were fixed in 10 per cent chilled formol, 0 Q,..., 5 QC, and frozen-sectioned. The sections were further incubated with the substrate having the following constituents at 37 QC for 20 minutes.