1. From the Laboratory of Biochemical Neuroendocrinology (M.D., J.M., A.Z., S.P., N.G.S., A.P.) and Laboratory of Neuropeptide Structure and Metabolism (D.G., C.L.), Clinical Research Institute of Montreal, Montreal, Canada. Dr Zaid is presently at the Department of Biochemistry, Faculty of Medicine, Tripoli University, Tripoli, Libya.