The effect of feeding on cerebrospinal fluid corticotropin-releasing hormone levels in humans

Corticotropin-releasing hormone (CRH) is a neuropeptide thought to play a r ole in appetite regulation. In this report, we used a serial cerebrospinal fluid (CSF) sampling technique to examine the relationship between CSF CRH, plasma ACTH and cortisol and perceptions of hunger and satiety in fasting and sated volunteers. CSF was withdrawn continuously from 11:00 AM to 5:00 PM via an indwelling subarachnoid catheter. Blood was withdrawn every 10 mi n via an antecubital vein catheter. Fed subjects received a meal at 1:00 PM . Subjects who were fed had lower post-prandial ratings on hunger scales an d higher ratings on satiety scales. Fed subjects also had slightly lower le vels of CSF CRH after feeding. Furthermore, fed subjects had higher ACTH an d cortisol concentrations in the first 3 h; by the fourth h the opposite wa s true. Our findings do not support the hypothesis that CNS CRH is a centra l satiety factor in the human. Instead our Endings of slightly diminished C SF CRH levels after feeding may be accounted for by the rises in glucocorti coids and their associated negative feedback effects on CNS CRH. Alternativ ely, our Endings could also reflect changes in CRH levels associated with f eeding in multiple brain areas and in the spinal cord with the net effect b ring in the negative direction. (C) 2001 Elsevier Science B.V. All rights r eserved.