The gut-brain peptide cyclo(His-Pro) is secreted in a pulsatile fashion in fasting humans.
Histidyl-proline diketopiperazine (CHP) is a cyclic dipeptide that is found in many animal tissues, most notably brain and gut. It has been found to have a variety of biologic actions and has been postulated to play a role in appetitive behavior and energy metabolism. This study was conducted in order to characterize the secretory pattern of CHP during a 24 h fast. Four subjects (2 obese and 2 lean) were studied during the latter 24 h of a 36 h fast. Blood was sampled every 10-15 min and assayed for CHP concentration using a specific radioimmunoassay. Analysis revealed that circulating CHP oscillates in humans and that diurnal variation occurred but only in the obese subjects.
Department of Medicine, Louisiana State University School of Medicine, New Orleans 70112.
D
D
Herminghuysen
C
C
Cook
H
H
Thompson
D
D
Bostick
F
F
Lee
L
L
Stokes
C
C
Hilton
C
C
Prasad
D000328:Adult; D005215:Fasting / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010456:Peptides, Cyclic / Q000378:metabolism*; D010507:Periodicity; D010879:Piperazines / Q000378:metabolism*
D010456:Peptides, Cyclic; D010879:Piperazines; C015924:histidyl-proline diketopiperazine