Changes in hypothalamic neuropeptide Y and monoaminergic system in tumor-bearing rats: pre- and post-tumor resection and at death.
BACKGROUND
Cancer anorexia is influenced by the neuropeptidergic and monoaminergic systems. We hypothesize that serotonin (5-HT), dopamine (DA) and neuropeptide Y (NPY) concentrations in paraventricular (PVN), ventromedial (VMN), and lateral hypothalamus (LHA) areas are abnormal in tumor-bearing rats.


METHODS
Fifty-five Fischer rats (240-280 g) were divided into MCA tumor-bearing (TB), nontumor-bearing (NTB), pair-fed (PF), TB sacrificed at the end of experiment (TB-Terminal), TB resection (TB-Resection), NTB sham-operated (NTB-Sham) and pair-fed sham-operated (PF-Sham) groups. Rats were sacrificed at onset of anorexia (TB, NTB, and PF) and 9 days after tumor resection (TB-Resection, NTB-Sham, PF-Sham, and TB-Terminal). Bilateral PVN, VMN, and LHA were harvested for NPY, 5-HT, and DA analyses.


RESULTS
Food intake decreased in TB versus NTB (P < .05). In TB versus NTB, an increase of 5-HT in PVN and VMN occurred with a concomitant decrease in DA. NPY in PVN, VMN, and LHA decreased (P < .05). In TB-Resection versus NTB-Sham, 5-HT, DA, NPY, and FI normalized after tumor resection.


CONCLUSIONS
Cancer anorexia is associated with abnormal serotonin, dopamine, and NPY concentrations, expressed by an increase in 5-HT and a decrease in DA and NPY. After tumor resection, these alterations normalized, providing evidence that the levels of these substances change with anorexia in tumor-bearing rats.
Surgical Metabolism and Nutrition Laboratory, Neuroscience Program, Department of Surgery, University Hospital, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
Eduardo J b
EJ
Ramos
Susumu
S
Suzuki
Michael M
MM
Meguid
Alessandro
A
Laviano
Tomoi
T
Sato
Chung
C
Chen
Undurti
U
Das
D000818:Animals; D001823:Body Composition; D001835:Body Weight; D004298:Dopamine / Q000032:analysis*; D004435:Eating; D007031:Hypothalamus / Q000737:chemistry*; D008297:Male; D009374:Neoplasms, Experimental / Q000378:metabolism* / Q000601:surgery; D009478:Neuropeptide Y / Q000032:analysis*; D051381:Rats; D011916:Rats, Inbred F344; D012701:Serotonin / Q000032:analysis*
D009478:Neuropeptide Y; D012701:Serotonin; D004298:Dopamine