| abstract |
Hexapeptides of the formula: n n H-Arg-Tyr-X-Gly-Phe-Y-Z n n wherein X is D-Ala, D-Met, D-Leu, D-Pro, D-His, D-Trp or D-Phe; Y is D-Leu, D-Met, D-Pro or D-Lys; and Z is --OH, --NH 2 , or --NHC 2 H 2n+1 where n is 1, 2, 3, or 4 or a pharmaceutically acceptable salt thereof, exert an analgesic effect in warm-blooded animals upon intravenous administration. |