The identity of chemical and hormonal properties of the thyrotropin releasing hormone and pyroglutamyl-histidyl-proline amide

Abstract The structure of L-pyroglutamyl- l -histidyl- l -proline amide (I) is in agreement with all Qf the known chemical and hormonal properties of the thyrotropin releasing hormone (TIM) from porcine hypothalami. This structural interpretation is probably applicable to the THE of other mammalian species, and is chemically based on the chromatographic identity in seventeen diversified systems and is biologically based on a quantitative comparison of the hormonal activities of the natural and synthetic products. This formulation of structure represents the elucidation of the first of the hypothalamic hormones that have been sought for so long.