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Biomedical subjects

Y Yawata

Publications and source records attributed to Y Yawata.

At least 163 records · Page 9Linked to original sources
PubMed1980

Glucagon-like substance in the canine brain.

Significant amounts of glucagon immunoreactivity (GI) and glucagon-like immunoreactivity (GLI) were found in two portions of the canine brain-the hypothalamus and brain stem. Ratios of GLI to GI were low in the hypothalamus, and variable but low in the brain stem. Dilution curves of the extracts from both regions showed similar patterns to that of glucagon in radioimmunoassay using specific (30K) and cross-reacting (YG9) antisera. The hypothalamic extract contained a larger amount of 3,500 MW fraction comparable to glucagon and a lesser amount of 9,000 MW fraction resembling proglucagon. While displacement of 125I-glucagon from the rat liver cell membrane by the main fraction of the hypothalamus was compatible with that of glucagon, activation of adenylate cyclase by the hypothalamus extract was higher than glucagon and that by the extract of the brain stem was lower than glucagon. Although purification was not sufficient and specific binding of circulating glucagon to the brain has not been overlooked, the hypothalamic extract at least contains material immunologically and probably biologically resembling glucagon.

Adenylyl Cyclases↗
PubMed1980

Membrane protein phosphorylation and protein kinases in normal and hereditary spherocytosis red cells.

Membrane protein phosphorylation by protein kinases in normal red cells takes place mainly on band 2 at the basal activity, and on bands 1 and 2.1 in the presence of cyclic 3':5'-adenosine monophosphate. Calcium precipitates preferentially bands 1 and 2.1 on extracted membrane proteins, and inhibit the membrane protein phosphorylation. Phosphorylation of endogeneous membrane proteins is diminished in red cells of some patients with hereditary spherocytosis (HS), partly corresponding reciprocally to MCHC, % spherocytes and reticulocytosis in peripheral blood of these patients, although the enzymatic activities of glyceraldehyde-3-phosphate dehydrogenase as a marker of the inner surface of red cell membranes are maintained normally in these red cells. The pattern of membrane protein fractions in HS red cells as endogeneous substrates for phosphorylation reactions is almost identical to that in normal red cells. Activities to phosphorylate casein or histone as exogeneous substrates are normal in HS red cell ghosts.

Acetylcholinesterase↗
PubMed1977

Association of decreased membrane protein phosphorylation with red blood cell spherocytosis.

A close association between sphering of human red cells and deficient phosphorylation of their membrane proteins has been documented in three spearate situations. Red cells rendered spheroidal by exposure to: (1) elevated temperatures; (2) two sulfhydryl inhibitors (N-ethylmaleimide or paramercuribenzoate); or (3) in the genetic situation of hereditary spherocytosis--all manifest deficient phosphorylation of endogenous membrane proteins by ATP. In the two former cases, we have noted an exact association between the onset of red cell sphering (e.g., as temperatures rose above 48 degrees C or N-ethylmaleimide concentrations exceeded 2 mumoles/ml RBC) and the development of deficient ghost protein phosphorylation.

Adenosine Triphosphate↗
PubMed1976

A possible role for cyclic nucleotides in the regulation of erythrocyte shape and permeability.

Erythrocytes treated with vinblastine or colchicine become spheroidal, more permeable to sodium, and of diminished deformability; upon reinjection they are rapidly sequestered and destroyed in the spleen. These deleterious effects are competitively inhibited by the cyclic nucleotides, guanosine 3',5'-monophosphate or adenosine 3',5'-monophosphate. The data suggest that cyclic nucleotides may be involved in normal erythrocyte shape and survival by interacting with membrane components that also react with vinblastine and colchicine. Similar interactions have been noted previously in diverse proliferating cells as well.

Cell Membrane Permeability↗