Energy-dependent uptake of arsenite by rat liver mitochondria

Steady state kinetics of energy-dependent Ca2+ uptake in rat liver mitochondria.

The divalent cation ionophore A23187 has been used to examine the steady state kinetics of energy-dependent Ca2+ uptake with /3-hydroxybutyrate as oxidizable substrate, and these results have been compared to the kinetic parameters obtained with succinate as the available energy source. The kinetics are sigmoidal with the free Ca*+ concentration at half-maximal respiratory stimulation (K,,,,) e...

Steady State Kinetics of Energy-dependent Ca2+ Uptake in Rat Liver Mitochondria*

The divalent cation ionophore A23187 has been used to examine the steady state kinetics of energy-dependent Ca2+ uptake with /3-hydroxybutyrate as oxidizable substrate, and these results have been compared to the kinetic parameters obtained with succinate as the available energy source. The kinetics are sigmoidal with the free Ca*+ concentration at half-maximal respiratory stimulation (K,,,,) e...

Uptake of protoporphyrin IX by isolated rat liver mitochondria.

Rat liver mitochondria accumulate protoporphyrin IX from the suspending medium into the inner membrane in parallel with the magnitude of the transmembrane K+ gradient (K+in/K+out). Only protoporphyrin IX taken up in parallel with the transmembrane K+ gradient is available for haem synthesis. Coproporphyrins (isomers I and III) are not taken up by the mitochondria. The results support the sugges...

The uptake of silicic acid by rat liver mitochondria.

1. To gain insight into a putative role for mitochondria in silicon metabolism, mitochondrial uptake (by which it is meant the removal from the medium) of silicic acid [Si(OH)4] was studied under conditions minimizing SI(OH)4 polymerization. 2. Measurements of mitochondrial respiration and swelling indicated indirectly a significant uptake of Si(OH)4 as a weak acid, but this was not confirmed w...

The uptake of thyroxine and triiodothyronine by rat-liver mitochondria.