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.
Herminghuysen
D
D
Department of Medicine, Louisiana State University School of Medicine, New Orleans 70112.
Cook
C
C
Thompson
H
H
Bostick
D
D
Lee
F
F
Stokes
L
L
Hilton
C
C
Prasad
C
C
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