title: Pharmacokinetic evaluation of superactive analogues of growth hormone-releasing factor (1-29)-amide.
abstract: D-amino acid-substituted analogues of growth hormone-releasing factor 1-29)-amide with superagonist activities in the rat were examined for increased plasma half-life and resistance to degradation in vivo. After IV injection, half-lives of the analogues were in the range 4.7-7.4 min, none of which was significantly different from that of the parent compound (6.2 min). Following SC injection, 4.6-7.2% of the dose of the analogues reached the circulation compared with 5.1% of the parent compound. Conformational restraints introduced into the N-terminal region of the molecule, which gave enhanced potency, did not alter the susceptibility of the peptide to proteolytic degradation.
mesh_terms: D000818:Animals; D001682:Biological Availability; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006207:Half-Life; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D010446:Peptide Fragments / Q000493:pharmacokinetics*; D051381:Rats; D017337:Sermorelin
chemical_list: D010446:Peptide Fragments; D017337:Sermorelin; D013007:Growth Hormone-Releasing Hormone