Peptides having the formula:
A.sub.0 -A.sub.1 -A.sub.2 -A.sub.3 -A.sub.4 -A.sub.5 -A.sub.6 -A.sub.7
-A.sub.8 -A.sub.9 -A.sub.10
wherein A.sub.0 is selected from hydrogen or an acyl group; A.sub.10 is a
hydroxyl group or an amino acid amide; and A.sub.1, A.sub.2, A.sub.3,
A.sub.4, A.sub.5, A.sub.6, A.sub.7, A.sub.8, and A.sub.9 are amino acyl
residues as defined herein.
