Lack of interaction between peripheral injection of CCK and obestatin in the regulation of gastric satiety signaling in rodents.
Obestatin is a new peptide for which anorexigenic effects were recently reported in mice. We investigate whether peripheral injection of obestatin or co-injection with cholecystokinin (CCK) can modulate food intake, gastric motor function (intragastric pressure and emptying) and gastric vagal afferent activity in rodents. Obestatin (30, 100 and 300 microg/kg, i.p.) did not influence cumulative food intake for the 2h post-injection in rats or mice nor gastric emptying in rats. In rats, obestatin (300 microg/kg) did not modify CCK (1 microg/kg, i.p.)-induced significant decrease in food intake (36.6%) and gastric emptying (31.0%). Furthermore, while rats injected with CCK (0.3 microg/kg, i.v.) displayed gastric relaxation, no change in gastric intraluminal pressure was elicited by obestatin (300 microg/kg, i.v.) pre- or post-CCK administration. In in vitro rat gastric vagal afferent preparations, 20 units that had non-significant changes in basal activity after obestatin at 30 microg responded to CCK at 10 ng by a 182% increase. These data show that obestatin neither influences cumulative food intake, gastric motility or vagal afferent activity nor CCK-induced satiety signaling.
Gourcerol
G
G
CURE/Digestive Diseases Research Center, Department of Medicine, Division of Digestive Diseases, University of California Los Angeles, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
Million
M
M
Adelson
D W
DW
Wang
Y
Y
Wang
L
L
Rivier
J
J
St-Pierre
D H
DH
Taché
Y
Y
D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology*; D004347:Drug Interactions; D004435:Eating / Q000187:drug effects*; D005746:Gastric Emptying / Q000187:drug effects* / Q000502:physiology; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009924:Organ Culture Techniques; D036361:Peptide Hormones / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012528:Satiety Response / Q000187:drug effects*; D013270:Stomach / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D014630:Vagus Nerve / Q000187:drug effects* / Q000502:physiology
D036361:Peptide Hormones; C505798:obestatin, rat; D002766:Cholecystokinin