Evaluation of Histidine Decarboxylase (HDC) Activity and Human Histamine Receptor 3 (H3R) and HDC mRNA Levels

Abstract

Histamine plays pleiotropic roles in human pathophysiology that are dependent on both its ability to be synthetized in a given environment and the cell-specific combination of histamine receptors expressed in the different human cell types. At present, characterization of the molecular basis of the tissue-specific roles of the histamine metabolism-related elements requires further research efforts to fully explain the multiple roles that histamine plays in human pathophysiology and to develop new intervention strategies derived from this knowledge. In this chapter, we describe some methods used in our laboratory for many years to investigate histidine decarboxylase (HDC) and histamine receptors (HRs) in different human cell types and tissues. These are a radiolabeled method for HDC activity measurement and quantitative real-time polymerase chain reaction (qPCR) methods for quantification and transcript analyses of human HDC and histamine receptor type 3 (H3R).