Histamine H2 receptor radioligands: triumphs and challenges

Since the discovery of the histamine H-2 receptor (H2R), radioligands were among the most powerful tools to investigate its role and function. Initially, radiolabeling was used to investigate human and rodent tissues regarding their receptor expression. Later, radioligands gained increasing significance as pharmacological tools in in vitro assays. Although tritium-labeling was mainly used for this purpose, labeling with carbon-14 is preferred for metabolic studies of drug candidates. After the more-or-less successful application of numerous labeled H2R antagonists, the recent development of the G protein-biased radioligand [H-3]UR-KAT479 represents another step forward to elucidate the widely unknown role of the H2R in the central nervous system through future studies.

Automated summary

Radioligands have been a powerful tool in investigating the histamine H-2 receptor (H2R) and its functions, with tritium labeling primarily used for in vitro assays and carbon-14 labeling preferred for metabolic studies. The recent development of a G protein-biased radioligand represents a step forward in understanding the potentially unknown role of H2R in the central nervous system through future studies.