The therapeutic utility of a human immunodeficiency virus type 1 (HIV-1) protease inhibitor may depend on its intracellular concentration, which is a property of its uptake, metabolism, and/or efflux. Previous studies in our laboratory indicated that the addition of alpha 1 acid glycoprotein (alpha 1 AGP) to the medium markedly increased the amount of the drug required to limit infection in vit...

Vesicles have been prepared by mild sonication of a purified inner membrane fraction from rat liver mitochondria. Such vesicles demonstrate an energy-dependent net concentrative uptake of inorganic phosphate in the absence of added Na+, Ca’+, or ionophores. Phosphate uptake can be supported by a variety of substrates including /?-hydroxybutyrate, succinate, and ascorbate + tetramethylphenylened...

Radioactive isotopes of strontium, mainly Sr, may considerably contribute to the total activity of long-lived fission products released into the environment in nuclear accidents. Consequently, the ingestion of strontium radionuclides with contaminated foodstuffs may result in a significant internal radiation exposure of members of the public. The committed radiation dose dependents significantl...

Rainbow trout (Oncorhynchus mykiss) retain the majority of lactate produced during exhaustive exercise within white muscle. Previous studies have suggested that this retention is partially via a re-uptake of released lactate. The purpose of this work was to study lactate uptake using trout white muscle sarcolemmal vesicles. Lactate uptake by trout white muscle is partially through a low-affinit...

The HCT-15 human colon cancer cell line has a Na(+)-dependent carrier-mediated transport system for the uptake of glycerol. A similar transport system has been suggested to be present also in the small intestine and is of interest with regard to its role in the absorption of glycerol and possibly some structurally related compounds. To help clarifying functional characteristics of such glycerol...

Rat oatp1 (Slc21a1) and oatp2 (Slc21a5) transport many structurally unrelated endogenous and exogenous compounds across the sinusoidal membrane of hepatocytes in a sodium-independent manner. There are several potential protein kinase A (PKA) and protein kinase C (PKC) phosphorylation sites in both rat oatp1 and oatp2 proteins, suggesting that PKA and/or PKC may play a role in regulating their f...

It has already been demonstrated that pitavastatin, a novel potent HMG-coenzyme A reductase inhibitor, is taken up into human hepatocytes mainly by organic anion transporting polypeptide (OATP) 1B1. Because OATP2B1 is also localized in the basolateral membrane of human liver, we took two approaches to further confirm the minor contribution of OATP2B1 to the hepatic uptake of pitavastatin. Weste...

Tiagabine (TGB) and vigabatrin (VGB) are two novel anticonvulsant compounds reported to exert their pharmacological effects via an action on the gamma-aminobutyric acid (GABA) system. We have investigated the effects of acute exposure of these drugs on the uptake of GABA into rat cortical astrocytes in primary culture. Astrocytes were prepared from the cerebral cortices of one day-old rat pups ...

1. Uptake studies using radioactive octopamine have revealed that the larval lantern of the Photuris firefly possesses a concentrative, high-affinity uptake system for octopamine. This compound has been shown previously to be the neurotransmitter of the photomotor neurones. 2. Imipramine is a potent inhibitor of the uptake of octopamine in the lantern. At 10~moll~', it reduces specific uptake o...

Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in treating numerous ailments and diseases. Hence, inventing strategies to tune cellular arsenic uptake based on purpose is striking. Here, we describe an approach in which the arsenit...