Expression of the histamine receptor in Xenopus oocyte and its application to the histamine sensor

We developed a receptor-mediated biological sensor for real time detection of histamine derived from granules of mast cell and basophils. A human histamine receptor gene was cloned by polymerase chain reaction and its mRNA was injected into Xenopus oocyte. After incubation for 2–3 days, the histamine receptor was expressed in the cell membrane of the oocyte. When the oocyte was activated by histamine, a calcium-activated chloride channel was opened, and the chloride ions in the oocyte flowed to the outside. The chloride ion current intensity was correlated with the histamine concentration. The histamine sensitivity of the oocyte was sufficient to allow comparison with other methods histamine analyses, such as enzyme immunoassay or HPLC analysis. The oocyte sensor system described here is a new chemical sensor system using receptor-mediated biological reactions.