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Biomedical subjects

T Ohsawa

Publications and source records attributed to T Ohsawa.

At least 127 records · Page 7Linked to original sources

A rapid and large-scale isolation of renin from mouse submaxillary gland by pepstatin-aminohexyl-agarose affinity chromatography.

A pressor enzyme, renin, was purified about 60-fold by chromatography on an affinity column including pepstatin-aminohexyl-agarose with a high yield of 83% from the homogenate of adult mouse submaxillary glands. The renin obtained by the one-step purification was electrophoretically homogenous on SDS-polyacrylamide gel and was as active as an absolutely pure renin. The renin purified by the affinity column could be separated into five active components by chromatography on CM-cellulose. Each of these renins gave a symmetrical elution profile on the CM-cellulose column and a discrete protein band on polyacrylamide gel electrophoresis at pH 8.6. Administration of nanogram quantities of each of the two major renin fractions to nephrectomized rats caused a sustained rise of blood pressure and decrease in sensitivity of the animal to angiotensin II. This rapid and large-scale purification method using pepstatin-aminohexyl-agarose eliminates all four fractionation steps reported previously for the isolation of mouse submaxillary gland renin.

Animals↗

Application of liposomal membranes to the analysis of the triggering mechanism of sperm acrosomal reaction.

The analysis of the triggering mechanisms of the sperm acrosomal reaction was attempted by using multilamellar liposome model membranes. The permeability of liposomes composed of egg lecithin, cholesterol and dicetylphosphate was increased by addition of the acrosome reactive substance which was obtained from the jelly coat of the sea urchin, Hemicentrotus pulcherrimus. An identical but more rapid response was also observed with liposomes containing sialoglycosphingolipids isolated from spermatozoa of the sea urchin. CA++ ions enhanced the reaction with both types of liposomes. The multilamellar liposomes were found to be useful as a model membrane of the sperm acrosomal reaction, and an involvement of sialoglycosphingolipids in the sperm acrosomal reaction was suggested.

Acrosome↗