Figure 2. Tricyclic compounds with known physiologic effects but poorly defined or multiple signaling mechanisms.

The list of trimeprazine analogs (tricyclic compounds) that increased IRS2 mRNA expression more than the 95th percentile or less than the 5th percentile (P < 0.05) in isolated human islets. The reported binding affinity toward H1R or α1-adrenergic was obtained from The Binding Database (http://www.bindingdb.org/bind/index.jsp). α1a , α1-adrenergic receptor; conc, concentration; H1R, histamine H1 receptor; mAChR, muscarinic acetylcholine receptor; SE, standard error.