Cellular Uptake and Release Studies for Receptor Pharmacology

Our service examines the effects of a compound on receptor or transporter systems in live cells. Assays are conducted on either primary or immortalized cells lines, with cell culture is undertaken by us.

Cellular uptake assays can be used to measure the transport or internalization of labeled compounds into cells or the potency of unlabeled test compounds in inhibiting this transport.  Labeled substances can be neurotransmitters, metabolites, drugs or proteins.  

Applications include: 

• Determination of IC₅₀ values for test compounds against cellular uptake of radiolabeled neurotransmitters. 
• Determination of IC₅₀ values for test compounds against uptake of tritium or ¹⁴C-labeled metabolites or drugs. 
• Cellular uptake and internalization of ¹²⁵I-labeled proteins. 

Cellular release assays can be used to quantify the efflux of labeled substances from cells. Efflux can be via membrane ion channels, membrane transport or from cell lysis.  

Applications include:

• ⁸⁶Rb⁺ rubidium efflux assay for quantification of drug effects on stimulation or inhibition of  ligand-gated ion channel activity (nicotinic). 
• Efflux of ³H and ¹²⁵I-labeled drugs from cells via transport.

Example Data: Cellular Uptake Assay

Inhibition of [³H]dopamine uptake into rat brain synaptosomes by the dopamine transport inhibitors, GBR 12909 and cocaine (left), shown in comparison with inhibition of [³H]mazindol binding (right).