Biomedical subjects

C Colton

Publications and source records attributed to C Colton.

3 recordsLinked to original sources

PubMed1991

The effect of xanthine/xanthine oxidase generated reactive oxygen species on synaptic transmission.

The effect of reactive oxygen species generated by the interaction of xanthine and xanthine oxidase on synaptic transmission was examined at the squid giant synapse and the lobster neuromuscular junction. Exposure of these synaptic regions to xanthine/xanthine oxidase produced a significant depression in evoked release, with no change in either resting membrane properties or in the action potential. Addition of catalase to the xanthine/xanthine oxidase-containing media partially blocked the synaptic depression, indicating that H2O2 contributes to the synaptic changes induced by exposure to xanthine/xanthine oxidase. H2O2 applied directly to the perfusing media also produced a decrease in synaptic efficacy. The results demonstrate that reactive oxygen species, in general, depress evoked synaptic transmission.

Action Potentials↗

PubMed1978

Hemofiltration.

Explore the source record for details and available documents.

Humans↗

PubMedDate not supplied

Transcellular urea gradients cause minimal depletion of extracellular volume during hemodialysis.

Concern exists that increasingly high-efficiency dialysis will result in large urea gradients between intracellular and extracellular compartments (VI, VE) leading to large amounts of extracellular volume depletion (delta VE) and hemodynamic instability induced by rapid water flow from VE to VI. The authors investigated this question with a two-compartment model that provided estimates of VI, VE, and osmotically active intracellular and extracellular urea and nonurea concentrations during hemodialysis. The authors found that the urea gradient-induced transcellular water shift is only a very small fraction of VE, even with high urea clearance and short hemodialysis time. The net water shift was small because the urea and nonurea transcellular osmolar gradients were of similar magnitudes but in offsetting directions.

Body Fluids↗