ISOLATION OF N-ACETYLASPARTIC ACID FROM HYPOTHALAMIC TISSUE AND SIGNIFICANCE OF ITS ACTH-RELEASING ACTIVITY

During extensive fractionation of extractives of porcine hypothalami tissue, advanced steps were monitored by RIA for the activity of the corticotropin releasing factor (CRF). Two entities with CRF-activity were observed and identified. They were <GluOH and N-AcAspOH; both released ACTH at μg-levels. AspOH and <GluOH had comparable activity, but AsnOH, GluOH, GlnOH were inactive. N-AcAspOH, and N-AcGluOH, N-AcGlnOH, and <Glu-GluOH showed comparable activity. N-AcAspOH has been identified from brain tissue by many investigators and contemplated as a transmitter. The release of ACTH by N-AcAspOH is a new observation, and allows the concept that an N-AcAsp-peptide might be a hormone for release (or inhibition) of a pituitary hormone including corticotropin. © 1978.