RESUMO
Eating a high fat diet can lead to obesity, type 2 diabetes, and dopamine system dysfunction. For example, rats eating high fat chow are more sensitive than rats eating standard chow to the behavioral effects (e.g., locomotion and yawning) of dopaminergic drugs (e.g., quinpirole and cocaine). Daily dietary supplementation with 20% (w/w) fish oil prevents high fat diet-induced enhanced sensitivity to quinpirole-induced yawning and cocaine-induced locomotion; however, doctors recommend that patients take fish oil just two to three times a week. To test the hypothesis that intermittent (i.e., 2 days per week) dietary supplementation with fish oil prevents high fat diet-induced enhanced sensitivity to quinpirole and cocaine, rats eating standard chow (17% kcal from fat), high fat chow (60% kcal from fat), and rats eating standard or high fat chow with 20% (w/w) intermittent (e.g., 2 days per week) dietary fish oil supplementation were tested once weekly with quinpirole [0.0032-0.32 mg/kg, intraperitoneally (i.p.)] or cocaine (1.0-17.8 mg/kg, i.p.) using a cumulative dosing procedure. Consistent with previous reports, eating high fat chow enhanced sensitivity of rats to the behavioral effects of quinpirole and cocaine. Intermittent dietary supplementation of fish oil prevented high fat chow-induced enhanced sensitivity to dopaminergic drugs in male and female rats. Future experiments will focus on understanding the mechanism(s) by which fish oil produces these beneficial effects.
Assuntos
Cocaína/farmacologia , Dieta Hiperlipídica/efeitos adversos , Óleos de Peixe/farmacologia , Quimpirol/farmacologia , Animais , Cocaína/administração & dosagem , Suplementos Nutricionais , Agonistas de Dopamina/administração & dosagem , Agonistas de Dopamina/farmacologia , Inibidores da Captação de Dopamina/administração & dosagem , Inibidores da Captação de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Óleos de Peixe/administração & dosagem , Locomoção/efeitos dos fármacos , Masculino , Quimpirol/administração & dosagem , Ratos , Ratos Sprague-Dawley , Bocejo/efeitos dos fármacosRESUMO
Consuming a high fat diet can lead to many negative health consequences, such as obesity, insulin resistance, and enhanced sensitivity to drugs acting on dopamine systems. It has recently been demonstrated that dietary supplementation with fish oil, which is rich in omega-3 fatty acids, can prevent this high fat diet-induced enhanced sensitivity to dopaminergic drugs from developing. However, it is not known whether fish oil supplementation can reverse this effect once it has already developed. To test the hypothesis that dietary supplementation with fish oil will reverse high fat diet-induced enhanced sensitivity to quinpirole, a dopamine D2/D3 receptor agonist, male Sprague-Dawley rats were fed either standard chow (17% kcal from fat), high fat chow (60% kcal from fat), standard chow, or high fat chow supplemented with 20% (w/w) fish oil. Body weight, food consumption, and sensitivity to quinpirole-induced (0.0032-0.32 mg/kg) penile erections were examined throughout the course of the experiment. Eating high fat chow enhanced sensitivity of rats to quinpirole-induced penile erections (i.e. resulted in a leftward shift of the ascending limb of the dose-response curve). Dietary supplementation with fish oil successfully treated this effect, as dose-response curves were not different for rats eating standard chow and rats eating high fat chow with fish oil. These results suggest that in addition to preventing the negative health consequences of eating a high fat diet, fish oil can also reverse some of these consequences once they have developed.
Assuntos
Comportamento Animal/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Óleos de Peixe/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Suplementos Nutricionais , Dopaminérgicos/metabolismo , Agonistas de Dopamina/farmacologia , Resistência à Insulina/fisiologia , Masculino , Obesidade/tratamento farmacológico , Ereção Peniana/efeitos dos fármacos , Quimpirol/metabolismo , Quimpirol/farmacologia , Ratos , Receptores de Dopamina D2 , Receptores de Dopamina D3RESUMO
Eating a diet high in fat can lead to negative health consequences, including obesity and insulin resistance. Omega-3 polyunsaturated fatty acids (such as those found in fish oil) prevent high fat diet-induced obesity and insulin resistance in rats. Eating a high fat diet also enhances sensitivity of rats to the behavioral effects of drugs that act on dopamine systems (e.g. quinpirole, a dopamine D2/D3 receptor agonist). To test the hypothesis that dietary supplementation with fish oil prevents high fat diet-induced enhanced sensitivity to the behavioral effects of quinpirole (0.0032-0.32 mg/kg), male rats ate standard laboratory chow, high fat chow, standard chow with fish oil, or high fat chow with fish oil (20% w/w). After 5 weeks, rats eating high fat chow were more sensitive (e.g. leftward shift of the quinpirole dose-response curve) than rats eating standard chow to yawning induced by quinpirole. Dietary supplementation with fish oil prevented this effect. That is, quinpirole dose-response curves were not different between rats eating high fat chow supplemented with fish oil and standard chow fed controls. These data add to a growing literature showing the complex relationship between diet and dopamine systems, and the health benefits of fish oil.