The Opioid System in Rainbow Trout Telencephalon Is Probably Involved in the Hedonic Regulation of Food Intake

Abstract

We hypothesize that opioids are involved in the regulation of food intake in fish through homeostatic and hedonic mechanisms. Therefore, we evaluated in rainbow trout (Oncorhynchus mykiss) hypothalamus and telencephalon changes in precursors, endogenous ligands and receptors of the opioid system under different situations aimed to induce changes in the homeostatic (through fasted/fed/refed fish) and hedonic (through feeding fish a control or a palatable high-fat diet) regulation of food intake. No major changes occurred in parameters assessed related with the nutritional condition of fish (fasted/fed/refed), allowing us to suggest that the opioid system seems not to have an important role in the homeostatic regulation of food intake in rainbow trout. The responses observed in telencephalon of rainbow trout fed the palatable high-fat diet included a decrease in mRNA abundance of the opioid precursor penka, in a way similar to that known in mammals, and increased mRNA abundance of the opioid receptors oprd1 and oprk1 supporting a role for telencephalic opioid system in the hedonic regulation of food intake in fish.

Long-term regulation of fat sensing in rainbow trout (Oncorhynchus mykiss) fed a vegetable diet from the first feeding: focus on free fatty acid receptors and their signalling

“…In contrast, in previous study of the same RT, we observed a higher serotonin level in the telencephalon, which is the major centre for decision making that receives serotonin neurons inputs in fish, during a fasting period (24) . The telencephalon can be responsible for this hedonic sensation in RT (58) . In the same way, in this area, the precursor of dopamine (L-DOPA), a neurotransmitter that is a marker of the stress response, motivation and ill-being when high in a chronic situation or due to long-term effects of feeding (24) , was higher in RT fed the V diet.…”

Phenylpiracetam: molecular mechanisms of effects in obesity

“…Хемореактомный анализ указал на умеренные антиопиоидные эффекты фонтурацетама по отношению к опиоидным рецепторам типов мю / каппа / дельта (IC50 = 642 нМ, остальные молекулы 1030-9438 нМ). Метаанализ доклинических исследований подтвердил анорексигенные эффекты опиоидных антагонистов [32]. Антагонисты опиатов можно использовать при лечении компульсивного переедания [33].…”

Methods of machine learning and big data analysis to establish the molecular mechanisms of the effects of racetams on the metabolism of adipose tissue

“…Фармакологические исследования опиатов и их антагонистов показали, что ингибирование опиатных рецепторов может быть использовано для лечения булимии [38]. Настоящее исследование указало на антиопиоидные эффекты 4-фенилпирацетама для рецепторов подтипов мю/каппа/дельта (IC50=642 нМ, другие рацетамы 1030-9438 нМ).…”