Search PubMed⌕ Search

Biomedical subjects

H Hillman

Publications and source records attributed to H Hillman.

At least 55 records · Page 3Linked to original sources

The uptake and efflux of L-phenylalanine and L-tyrosine from rat brain cerebral cortex slices.

The uptake of radioactive l-phenylalanine and l-tyrosine into the tissue water of rat brain cerebral cortex slices was shown to have saturation kinetics. The apparent K(m) for the uptake of l-phenylalanine was 0.86mm and for l-tyrosine was 1.64mm; for phenylalanine the apparent V(max.) value was 0.64mumol/min per ml of tissue water, and for l-tyrosine it was 0.98mumol/min per ml of tissue water. The accumulation of the two amino acids by the tissue was depressed in the absence of O(2), at 0 degrees C, or in the presence of metabolic inhibitors. The influxes and effluxes of both l-isomers were more rapid than those of the d-isomers. Competition between these two amino acids and each with l-tryptophan in respect of uptake into tissue water was shown. Their rates of influx were faster, and rates of efflux were slower, in the presence than in the absence of Na(+). It was concluded that these amino acids were taken up by active transport via a carrier mechanism.

Animals↗

The uptake and efflux of glycine from rat cerebral-cortex slices.

The kinetics of the influx and efflux of radioactive l-glycine was studied in slices of rat cerebral cortex. The influx showed saturation kinetics and was inhibited by l-alanine. Influx was dependent on the presence of Na(+) ions and a metabolizable substrate. The efflux of glycine was accelerated by alanine. It was concluded that carrier-mediated facilitated diffusion was the mechanism of glycine uptake by, and efflux from, cerebral slices.

Adenosine Triphosphate↗