In vivo biological potency of rat and human growth hormone-releasing factor and fragments of human growth hormone-releasing factor.
The biological potency of the synthetic replicates of three peptides isolated from a human pancreatic tumor with growth hormone releasing activity and rat hypothalamic growth hormone-releasing factor was evaluated in conscious freely-moving rats and anesthetized rats. All 4 peptides are equipotent on a molar basis in their ability to stimulate GH secretion. Studies with synthetic fragments of the human derived material indicated that the amino-terminal amino acid is required for activity. Deletion of as many as 13 amino acids from the carboxy-terminal failed to decrease GH-releasing activity; however, deletion of 16 amino acids resulted in a significant decrease and deletion of 20 amino acids resulted in complete loss of bioactivity.
D000595:Amino Acid Sequence; D000818:Animals; D013006:Growth Hormone / Q000097:blood; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010446:Peptide Fragments; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone