Endogenous histamine is involved in tissue growth and cell proliferation. I
n accordance with a putative function of the H-3 receptor in this mitogenic
effect, we show that H-3-receptor mRNAs are expressed together with those
of the histamine-synthesizing enzyme in the embryonic liver and adipose tis
sue, and in various epithelia. Finally, we show that activation of recombin
ant H3 receptors enhances MAP kinase activity. (C) 2001 Elsevier Science Ir
eland Ltd. All rights reserved.