OBJECTIVE: To investigate whether there is a difference in sensitivity to a serotonin agonist, meta-chlorophenylpiperazine (mCPP), or cholecystokinin (CCK-8), an intestinal hormone that inhibits food intake, between the Osborne-Mendel (OM) rat, which becomes obese eating a high-fat diet, and the S5B/Pl (S5B) rat, which is resistant to dietary-induced obesity. RESEARCH METHODS AND PROCEDURES: OM and S5B rats were adapted to either a high-saturated-fat diet (56% energy as fat) or a low-fat diet (10% energy as fat) or to both for 14 days and then treated with several doses of mCPP or CCK-8. RESULTS: Treatment with mCPP reduced food intake in both strains of rats. The dose-response curve showed that the OM rats had an increased sensitivity to the serotonergic agonist. Animals eating the high-fat diet had less response to mCPP; and in the S5B rats, the response was significantly reduced. After treatment with CCK-8, there was a similar dose-related suppression of food intake in both the OM and S5B rats. DISCUSSION: These data are consistent with the hypothesis that the serotonin system in the S5B rat has a greater activity that could act to inhibit fat intake. The response to CCK was not significantly affected by strain or diet.
OBJECTIVE: To investigate whether there is a difference in sensitivity to a serotonin agonist, meta-chlorophenylpiperazine (mCPP), or cholecystokinin (CCK-8), an intestinal hormone that inhibits food intake, between the Osborne-Mendel (OM) rat, which becomes obese eating a high-fat diet, and the S5B/Pl (S5B) rat, which is resistant to dietary-induced obesity. RESEARCH METHODS AND PROCEDURES: OM and S5B rats were adapted to either a high-saturated-fat diet (56% energy as fat) or a low-fat diet (10% energy as fat) or to both for 14 days and then treated with several doses of mCPP or CCK-8. RESULTS: Treatment with mCPP reduced food intake in both strains of rats. The dose-response curve showed that the OM rats had an increased sensitivity to the serotonergic agonist. Animals eating the high-fat diet had less response to mCPP; and in the S5B rats, the response was significantly reduced. After treatment with CCK-8, there was a similar dose-related suppression of food intake in both the OM and S5B rats. DISCUSSION: These data are consistent with the hypothesis that the serotonin system in the S5B rat has a greater activity that could act to inhibit fat intake. The response to CCK was not significantly affected by strain or diet.
Authors: Christina S-Y Chen; Elias M Bench; Timothy D Allerton; Allyson L Schreiber; Kenneth P Arceneaux; Stefany D Primeaux Journal: Am J Physiol Regul Integr Comp Physiol Date: 2013-10-23 Impact factor: 3.619
Authors: Michael Michaelides; Michael L Miller; Gabor Egervari; Stefany D Primeaux; Juan L Gomez; Randall J Ellis; Joseph A Landry; Henrietta Szutorisz; Alexander F Hoffman; Carl R Lupica; Ruth J F Loos; Panayotis K Thanos; George A Bray; John F Neumaier; Venetia Zachariou; Gene-Jack Wang; Nora D Volkow; Yasmin L Hurd Journal: Mol Psychiatry Date: 2018-06-28 Impact factor: 15.992
Authors: J M Poret; F Souza-Smith; S J Marcell; D A Gaudet; T H Tzeng; H D Braymer; L M Harrison-Bernard; S D Primeaux Journal: Int J Obes (Lond) Date: 2017-11-20 Impact factor: 5.095