The material, to which the name ΓÇÿsomatostatinΓÇÖ was applied, is a peptide containing fourteen amino acids, which lacks the amide and pyroglutamic acid terminals that are characteristic of GnRH and TRH, but contains a disulphide bridge similar to that of ADH and oxytocin. Other molecular forms of somatostatin have been isolated, including a peptide of twenty-eight amino acids (the last fourteen amino acids are identical to those in somatostatin-14) and a still larger form, the prohormone, with a molecular weight of approximately 15,000.
