Search PubMed⌕ Search

Biomedical subjects

T Ozeki

Publications and source records attributed to T Ozeki.

At least 91 records · Page 5Linked to original sources

The effects of vitamin E on the indicator enzymes of organella membranes in the injured liver.

Acute and chronic liver damage was caused by the administration of either galactosamine or carbon tetrachloride. Consequently, the rats with damaged livers were killed after vitamin E was administered. The livers were removed and were homogenated. Indicator enzymes (5'-nucleotidase, arylsulfatase, cytochrome C oxidase and glucose-6-phosphatase) of organella membranes were measured in the homogenates of the normal and damaged livers. The effects of vitamin E resulted in the stabilizing of the impaired membranes of plasma, lysosome, mitochondria and microsome; (1) the abnormal decrease of 5'-nucleotidase activity and glucose-6-phosphatase activity, and the abnormal increase of arylsulfatase activity, which induced galactosamine or carbon tetrachloride, and (2) the abnormal decrease of cytochrome C oxidase activity induced by galactosamine- HCl, were normalized.

5'-Nucleotidase↗

A polyhydric phenol sulfokinase and chronic liver injury.

The sulfokinase, that transfers activated sulfate from PAPS (3'-phosphoadenosine-5'-phosphosulfate) to nitrocatechol sulfate was studied. 1. It is thought that the enzyme plays an important role in detoxication by the sulfation of polyhydric phenols in liver. 2. The enzyme had an optimum at pH 8.0 in Tris-acetate buffer. Km was 0.105 x 10(-3)M. The rate of conjugation was linear within 1 min. 3. The main distribution of the sulfokinase was found in the liver, lungs, spleen and various other organs in the rat. The activity of the enzyme in rat liver was the highest in soluble fraction. In chronic hepatic injury caused by carbon tetrachloride injection, the activity of the enzyme gradually decreased to below about one half of the control value.

Animals↗

Stomach ulcer and lysosomal cathepsin.

Gastric ulcers were induced in rats by i.m. injections of vitamin A, and i.p. injection of histamine, or injections of both vitamin A and histamine. The incidence of ulcer formation was highest in the vitamin A-histamine group. However, ulcer formation also occurred after the administration of vitamin A alone as a lysosomal labilizer. Furthermore, the vitamin A-histamine group showed a remarkably elevated cathepsin activity in the tissue of gastric wall. In the experiments of ulcer formation by vitamin A injections, the specific activity and the enzyme release of cathepsin were elevated already in the early stage after vitamin A administration. Consequently, cathepsin activity in stomach juice was remarkably elevated in the stage of the ulcer formation. In the clinic, the cathepsin activity in the mucous membrane of human gastric wall was remarkably high in the antrum and the angulus of the stomach, in which ulcer formation tends to occur most frequently. In view of these results, cathepsin in the stomach seems to play an important role in the formation of gastric ulcers.

Animals↗

Degradation of arylsulfate by hepatic microsomes.

The enzyme liberated by some treatments and the changes in arylsulfatase C activity in chronic hepatic damage were investigated in rat liver. 1. The enzyme activity liberated by ultrasound was the highest in the conditions studied. 2. Arylsulfatase C was assayed using p-nitrophenyl sulfate in 0.25 M Tris/acetate buffer as substrate. It is shown that this method can be used to measure arylsulfatase C activity in a mixture of arylsulfatases A and B. 3. The enzyme is mainly located in the microsomal fraction in rat liver. In toxic hepatic damage, the enzyme activity decreases from the early stage; decreasing markedly in chronic hepatic damage. The activity seems to reflect damage to the microsomes and therefore arylsulfatase C activity can be a good indicator of injury to liver microsomes.

Animals↗

Y-chromatin positive cells in the smear preparations of the gonad from a XX male.

An ambisexual male infant showed a normal female karyotype by the leukocyte culture technique in two different occasions. Cultured fibroblasts from the right gonad had also a 46, XX complement. They were Y-chromatin negative. To our surprise, Y-chromatin was observed in 96% of the nuclei in smears from the uncultured gonad. It is emphasized that the examination of the uncultured gonad by the quinacrine technique is mandatory in the study of "XX males".

Fibroblasts↗