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Biomedical subjects

H Ohtake

Publications and source records attributed to H Ohtake.

At least 199 records · Page 11Linked to original sources
PubMed1983

Structure and action of sperm activating peptides from the egg jelly of a sea urchin, Anthocidaris crassispina.

Three Sperm Activating Peptides (SAPs) have been isolated to homogeneity from the jelly coat of the eggs of a Japanese sea urchin, Anthocidaris crassispina, and two of them have been sequenced. At pH 6.8 they can stimulate the sperm respiration 20-30 fold, to the level in normal seawater (pH 8.2), and the half-maximal activation was achieved by SAPs as low as around 100 pM. The stimulative activity was both pH- and Na+-dependent. The chymotryptic fragments (res. 3-10) were 10(4)-10(5) times less active, and the thermolytic fragment (res. 4-10) was 10(6) times less active than the parent SAP. CD spectra of SAPs indicate that they have unordered structure in aqueous solution.

Amino Acid Sequence↗
PubMed1983

Sea urchin (Anthocidaris crassispina) egg zinc-binding protein. Cellular localization, purification and characterization.

Gel-filtration analysis of cytosol fraction obtained from unfertilized sea-urchin (Anthocidaris crassispina) eggs on Sephadex G-75 revealed the presence of two Zn-binding-protein fractions. The major Zn-binding protein fraction had a low molecular weight and a low absorbance at 280 nm, properties similar to those of the metallothionein found in the regenerating rat liver. These fractions were further purified by DEAE-cellulose and Sephadex G-50 chromatography. Homogeneity of the Zn-binding protein was judged by polyacrylamide-disc-gel electrophoresis and gel-permeation chromatography in the presence of 6 M-guanidinium chloride. The molecular weight determined by gel-permeation chromatography was 3900. This value is in good agreement with the minimum molecular weight calculated from the amino acid composition, which was 3655. Zn-binding protein is composed of 36 amino acid residues and the distinctive features include an extremely high content of cysteine, which accounted for one-third of the total amino acid residues, and a complete absence of aromatic amino acids, as well as of methionine, histidine and arginine. Zn-binding protein contained 4.1 g-atoms of zinc per mol and a trace of cadmium, but no copper, iron or calcium. The molar ratio of reactive thiol groups to metal ion was calculated to be 2.73:1. Possible roles of this Zn-binding protein in the homoeostasis of zinc in unfertilized sea-urchin eggs are discussed.

Amino Acids↗
PubMed1983

Effect of prostaglandin inhibition by indomethacin on renal function in alcoholic versus non-alcoholic cirrhotic patients.

The purpose of this study was to compare the effect of inhibition of renal prostaglandin synthesis on renal function in 11 patients with alcoholic cirrhosis and 11 with non-alcoholic cirrhosis. After indomethacin administration to the 11 alcoholic patients, the glomerular filtration rate (GFR) and effective renal plasma flow (RPF) decreased significantly (p less than 0.05), but were found to decrease more significantly in the non-alcoholic cirrhosis group. The plasma disappearance rate of indocyanine green was lower in the non-alcoholic group than the alcoholic group, and correlated inversely with the percent decrease in GFR and RPF after indomethacin. These results suggest that the augmented effect of indomethacin is greater in the non-alcoholic group than the alcoholic group, which may be related to the decrease in hepatic blood flow.

Cyclooxygenase Inhibitors↗