[ D - Ala 2 , ( Fs ) Phe 4 ] - Dynorphin 1 - - 13 - N H 2 ( DAFPHEDYN ) : A Potent Analog of Dynorphin 1 - 13

WALKER, J. M., D. H. COY, E. A. YOUNG, G. BALDRIGHI, S. F. SIEGEL, W. D. BOWEN AND H. AKIL. [D-AIa z, (F~)Phe4]-Dynorphin~_la-NH2 (DAFPHEDYN): A potent analog of dynorphin 1-13. PEPTIDES 8(5) 811-817, 1987.-Intracerebroventricular administration of the dynorphin analog, [D-Ala2,(Fs)Phe4]-dynorphint_l~-NH2 (DAFPHEDYN) in rats produced diuresis and profound analgesia. Both effects were antagonized by central administration of naltrexone or naloxone. Intravenous administration of 10, 25, and 50 mg/kg of DAFPHEDYN failed to induce diuresis. The increased potency of DAFPHEDYN was apparent from the failure of an equal dose of the parent compound (dynorphin 1-13) to produce diuresis and the failure of [D-Ala2]-dynorphin~_~:rNH2 to produce analgesia. Radioligand binding studies indicated the DAFPHEDYN retains the same degree of K selectivity as the parent compound (dynorphin 1-13) though a drop in affinity occurred. DAFPHEDYN may be of significant interest because it retains the essential pharmacology of the parent compound and exhibits marked in vivo potency.