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Catalogue number: CA200799
Product: H1 antagonist [mepyramine]
Selectivity: H1: 8.07 | H2: 5.37 | H3: >6
For the H1 expressing cell line, the serum-induced expression of SPAP was measured under basal and 1% serum-stimulated (maximal) conditions. Addition of CA200799 to the basal or serum-stimulated cells did not significantly alter basal and stimulated SPAP levels, demonstrating that CA200799 has no intrinsic agonist activity.
To determine the apparent KD for CA200799 at histamine H1 receptors, cells were treated with varying concentrations of histamine agonist alone, or in the presence of 1µM CA200799, and the serum-induced expression of SPAP measured. The apparent KD at H1 was calculated from the rightward shift of the agonist response curve in the presence of CA200799, compared to the response curve for the agonist alone.
Similar studies were conducted with the CA200799 ligand using recombinant CHO cell lines expressing either the human H2 receptor or the human H3 receptor and a cyclic AMP-responsive secreted placental alkaline phosphatase (SPAP) reporter gene. The apparent KD at H2 was calculated in the same way to that calculated for the human H1 receptor.