Bovine growth hormone fragment (1-133) has in-vitro somatomedin-like activity

Thrombin digestion of bovine growth hormone (1-191) resulted in cleavage of the peptide bond between amino acid residues 133 and 134. Native growth hormone and purified peptides (1-133) and (134-191) were assayed for somatomedin-like activity. Peptide (1-133), ranging in concentration from 0.15-15 nmol/l, stimulated in-vitro uptake of [3H]thymidine by rat costal cartilage. None of the other peptides was biologically active.