U-50,488 and the kappa receptor. Part II: 1991-1998

This review, Part II, follows an earlier article, Part I, published in volume 52 of this series. Part II is a discussion of centrally and peripherally acting kappa agonists which can be considered analogs of U-50,488. Included also are three classes of kappa agonists which fall outside of the scope of the general structure of U-50,488. These are benzodiazepines, phenothiazines and diazobicyclonanones. The discussion also covers other pertinent topics including labelled ligands and sigma receptor.