1. Overview
The peptide hormones are proteinous in nature and may have 3 to 200 amino acids residues. This class of hormones includes all the hormones of the hypothalamus and pituitary, as well as insulin and glucagon of pancreas. Peptide hormones are named based on their endocrine activity rather than their chemical structure; for example, growth hormone is thus named because one of its effects is to stimulate growth. The structure of a particular peptide hormone can vary among different species, with some homology between close relatives. Some small peptides are identical; for example, GnRH is identical among mammals but different in ...