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Biomedical subjects

F Palmieri

Publications and source records attributed to F Palmieri.

At least 181 records · Page 10Linked to original sources

A kinetic study of sulphate transport in rat liver mitochondria.

The kinetics of sulphate uptake catalysed by the dicarboxylate carrier were measured. The Km value for sulphate is about 0.3 mM. A completely competitive relation exists between the influxes of sulphate and malonate, whereas the relation between sulphate and phosphate is of the mixed type. The inhibition of sulphate influx by mersalyl and bathophenanthroline is similar to that of malonate influx and different from the inhibition of phosphate influx. It is considered that sulphate and malonate probably bind to the same locus on the carrier, whereas phosphate occupies a different site. The possible implications of this conclusion are discussed.

Animals↗

The transport of sulphate and sulphite in rat liver mitochondria.

1. The mechanism of sulphite and sulphate permeation into rat liver mitochondria was investigated. 2. Extramitochondrial sulphite and sulphate elicit efflux of intramitochondrial phosphate, malate, succinate and malonate. The sulphate-dependent effluxes and the sulphite-dependent efflux of dicarboxylate anions are inhibited by butylmalonate, phenylsuccinate and mersalyl. Inhibition of the phosphate efflux produced by sulphite is caused by mersalyl alone and by N-ethylmaleimide and butylmalonate when present together. 3. External sulphite and sulphate cause efflux of intramitochondrial sulphate, and this is inhibited by butylmalonate, phenylsuccinate and mersalyl. 4. External sulphite and sulphate do not cause efflux of oxoglutarate or citrate. 5. Mitochondria swell when suspended in an iso-osmotic solution of ammonium sulphite; this is not inhibited by N-ethylmaleimide or mersalyl. 6. Low concentrations of sulphite, but not sulphate, produce mitochondrial swelling in iso-osmotic solutions of ammonium malate, succinate, malonate, sulphate, or phosphate in the presence of N-ethylmaleimide. 7. It is concluded that both sulphite and sulphate may be transported by the dicarboxylate carrier of rat liver mitochondria and also that sulphite may permeate by an additional mechanism; the latter may involve the permeation of sulphurous acid or SO(2) or an exchange of the sulphite anion for hydroxyl ion(s).

Ammonium Sulfate↗