| abstract |
A B S T R A C T Tetrapeptide amides of the formula wherein R1, R8, Rx, B and D represent certain specified substituent groups. The compounds exhibit pharmacological activity when tested in vitro in the transmurally stimulated guinea pig ileum preparation indicating their affinity for opiate receptor sites, and also in vivo tests, with intravenous administration, indicating their analgesic effects, and hence their utility as analgesic agents. |