The influence of histamine on epithelial cell proliferation in the jejunum of the rat.

1. The influence of histamine and histamine receptor blockade on the mitotic rate in epithelial cell proliferation in epithelial cells lining the crypts of Lieberkühn in rat jejunum was studied. 2. Histamine injection resulted in an increase in the mitotic rate. This increase in mitotic rate was blocked by metiamide but not by mepyramine. 3. Prevention of histamine synthesis by alpha-methylhistidine administration did not alter the mitotic rate. 4. The mechanism by which histamine may influence crypt cell proliferation and possible role of cyclic GMP in this mediation are discussed.¿