Radioligand

A radioligand is a radioactive biochemical substance (in particular, a ligand) that is used for diagnosis or for research-oriented study of the receptor systems of the body.

The radioligand is injected into the pertinent tissue, or infused into the bloodstream. It binds to its receptor. When the radioactive isotope in the ligand decays it can be measured, e.g., by positron emission tomography.

The transport of the radioligand is described by receptor kinetics.

History
Radioligands are acredited for making possible the study of biomolecular behaviour, a previously mysterious area of research that had evaded researchers. With this capacity radioligand techniques enabled researchers to identify receptor devices within cells.

Radioactive isotopes commonly used

 * Tritium 3H
 * Carbon-14
 * Sulfur-35
 * Iodine-131

List of radioligands

 * (18F)altanserin
 * (11C)ketanserin