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 been used in the diagnosis of deficiencies in growth hormone secretion. Tesamorelin, under the trade name Egrifta, received U.S. Food and Drug Administration approval in 2010 for the treatment of lipodystrophy in HIV patients under highly active antiretroviral therapy, and, in 2011, was investigated for effects on certain cognitive tests in the elderly. As a category, the use of GHRH analogs by professional athletes may be prohibited by restrictions on doping in sport because they act as growth hormone secretagogues. Growth hormone–releasing hormone Growth hormone–releasing hormone (GHRH), also known as somatocrinin or by several other names in its endogenous forms