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Biomedical subjects

B Shapiro

Publications and source records attributed to B Shapiro.

At least 361 records · Page 20Linked to original sources
PubMed1971

The purification and properties of microsomal palmitoyl-coenzyme A synthetase.

The isolation and purification of palmitoyl-CoA synthetase from rat liver microsomes is described. Several methods suitable for enzyme assay are described. The general properties and kinetic parameters of the purified enzyme were determined and are discussed in relationship to microsomal fatty acid activation.

Albumins↗
PubMed1971

Effect of cell size on epinephrine- and ACTH-induced fatty acid release from isolated fat cells.

Free fatty acid release from fat cells, obtained from epididymal adipose tissue of rats of different sizes, was found to be dependent on the cell surface area, regardless of the age of the animals. The same result was found with cells of different sizes from the same animal. These results, when related to in vivo conditions, would indicate that for the same adipose tissue mass, activity would decrease with increasing cell size. On the other hand, the total activity of a given tissue would increase by increasing the size of its cells.

Adipose Tissue↗
PubMed1970

The intracellular transport and distribution of cysteamine phosphate derivatives.

Radioautography and extractive techniques were used to analyze the transport of cysteamine phosphate and its derivatives in salamander oocytes. The quantitative relations among the processes involved - membrane permeation, enzymatic dephosphorylation, binding through mixed disulfide formation, and cytoplasmic diffusion - were elucidated. Within the detection limits, all of the intracellular material is present as dephosphorylated derivatives. Cytoplasmic diffusion is effectively slowed by binding (the "chromatographic" effect) and makes an appreciable contribution to cellular flux rates. As a consequence, one can observe by radioautography a cortical diffusion ring which spreads inward as a function of influx time, while also increasing in peak density because of the finite membrane permeability. Good agreement was found between the transport parameters determined by radioautography and those from influx data for the whole oocyte. The ratio of nuclear to cytoplasmic concentrations of the cysteamine phosphate derivatives at equilibrium is about 0.4. The nuclear membrane is, however, a negligible barrier to transport, and the asymmetry appears to arise primarily from the quantity and sulfhydryl content of the binding proteins in the two compartments.

Animals↗