US Patent 7732398 Medicinal uses of mu-opioid receptor agonists

The present invention provides methods for stimulating mu-opioid receptors with agonist peptides in a mammal in need thereof. The methods comprise administering to the mammal an effective amount of a selective mu-opioid receptor agonist peptide that comprises at least two α-amino acid residues. At least one of the amino acid residues has a positive charge. The amino acid residue in the first position is a tyrosine or tyrosine derivative. The amino acid in the second position is a D-α-amino acid. The present invention also provides methods of treating a mammal suffering from conditions or diseases by administering to the mammal an effective amount of the peptides.