John Jacob Abel to successfully isolate the neutral base of epinephrine by adding ammonium to highly concentrated extract, a method Abel himself tried but failed due to the use of low concentration of extract. After Takamine's success, Abel himself remarked, with great candor, "The efforts of years on my part in this once mysterious field of suprarenal, medullary biochemistry, marred by blunders as they were, eventuated, then, in the isolation of the hormone not in the form of the free base but in that of its monobenzoyl derivative." Together with L.G. Rowntree and B.B. Turner, Abel devised what they called a "vividiffusion" apparatus,
Growth hormone–releasing hormone Growth hormone–releasing hormone Growth hormone–releasing hormone (GHRH), also known as somatocrinin or by several other names in its endogenous forms and as somatorelin (INN) in its pharmaceutical form, is a releasing hormone of growth hormone (GH). It is a 44-amino acid peptide hormone produced in the arcuate nucleus of the hypothalamus. GHRH first appears in the human hypothalamus between 18 and 29 weeks of gestation, which corresponds to the start of production of growth hormone and other somatotropes in fetuses. GHRH is released from neurosecretory nerve terminals of these arcuate neurons, and is carried by the hypothalamo-hypophyseal portal system to