Influência do consumo de gordura interesterificada nos períodos iniciais do desenvolvimento sobre parâmetros de adição por morfina em ratas

Abstract

There is a high consumption of processed foods with interesterified fat (IF), which has replaced trans fat, given that it has shown harmful effects on health. Morphine is an opioid drug, widely used to alleviate acute and chronic pain, presenting high adicctive potential and increasing inadequate use. Considering that the phospholipids of the neural membranes can be modified by dietary fatty acids, to date, no study has evaluated possible influence of IF consumption on neuronal function, especially involving the opioid system and morphine, which became the aim of this study. Wistar rats were supplemented with soybean oil (SO) or IF during the gestational period and lactation, whose pups were maintained with the same maternal supplementation until the postnatal day (PND) 38. On PND 39, the animals were submitted to morphine-induced conditioned preference (CPP) protocol, elevated plus maze and hot plate tests. After the behavioral assessments, the immunoreactivity of molecular markers was evaluated in the hippocampus and spinal cord of the animals. The SO group showedmorphine preference in the CPP test and anxiety symptoms with morphine withdrawal while the IF group showed no preference or anxiety. In addition, the IF group presented greater sensibility to thermal stimulation. Besides, animals in the SO group receiving morphine showed increased dopamine D1 receptor and N-methyl-D-Aspartate receptor immunoreactivity in the hippocampus, whereas these changes were not observed in the IF group. Regardless of the morphine conditioning, the IF group showed increased kappa opioid receptors immunoreactivity in the spinal cord, which also showed a negative correlation with the thermal sensibility (r2=0.67). The findings here indicate that the chronic consumption of IF during the early stages of development may affect the opioid neurotransmission system, modifying the rewards responses related to this system. Considering that the endogenous opioid system is strongly involved in multiple physiological hedonic responses, as well as in the pharmacological response of opioid drugs, the continuity of these studies would be necessary.