1. From the Department of Pharmacology (F.L.S., J.C.W.Y., Y.L.S., K.O), Faculty of Medicine, The University of Hong Kong, and National Centre for Agri-Food Research in Medicine (K.K.W.A-Y., C.W.H.W., Y.L.S., K.O.), Departments of Animal Science and Physiology, University of Manitoba, Canada.