Chapter 13. Bradykinin B₂ receptors and signal transduction analyzed in NG108-15 neuroblastoma X glioma hybrid cells, B₂ receptor-transformed CHO cells and ras-transformed NIH/3T3 fibroblasts

This chapter discusses the molecular structure of mouse B₂ BK receptors based on its cDNA and functional characterization, describes B₂ receptors at the genetic and molecular level, and summarizes the results obtained for B₂ receptors expressed in xenopus oocytes and Chinese hamster ovary (CHO) cells. The chapter also describes signal transduction pathways in the downstream of B₂ BK receptors in NG108-15 neuroblastoma X glioma hybrid cells, which provide one of the basic mechanisms underlying nociception and neuronal activity modulation by BK. The chapter mentions B₂ BK receptor-mediated interaction between tyrosine kinase and phospholipase C signal pathways in ras-transformed NIH/3T3 fibroblast (DT) cells, where BK functions as a mitogen. The chapter also discusses various B₂ receptor-mediated inositol phospholipid metabolism. The activation of a mitogen-activated protein (MAP) kinase pathway may result in cell proliferation. In relation to nociception, and pain neurotransmission or neuromodulaion, BK serves as a transmitter or modulator. To do this, B₂ receptors induce changes in ion channel conductances, as a consequence of formation of second messengers or of protein phosphorylation.