Futhan is a serine protease inhibitor and medicine in the treatment of disseminated intravascular coagulation (DIC) and acute pancreatitis. It is metabolized quickly in vivo. Here we show that Futhan reversibly inhibits NMDA receptors in hippocampal neurons and GABA(A) receptors both in hippocampal neurons and in A549 cells, a human alveolar epithelial cell line. The effect of Futhan on GABA(A) receptors in A549 cells is much more potent than its effect on GABA(A) receptors in hippocampal neurons (IC(50): 0.9 μM V.S. 7.3 μM). Since GABA(A) receptors are also expressed in various non-neuronal tissues, particularly in airway epithelia and GABA promotes mucus production during asthma, our findings indicate that Futhan may be developed as a novel aerosolized therapeutic to treat asthma through blocking GABA(A) receptors in the lung.
