Effects of 17β-Estradiol on the Activity of Dopamine D2 Receptors in the Selection of Carbohydrate, Lipid and Protein Macronutrients in Females Rats (Healthy Rats)

Effects of 17β-Estradiol on the Activity of Dopamine D2 Receptors in the Selection of Carbohydrate, Lipid and Protein Macronutrients in Females Rats (Healthy Rats) - Overeating and obesity are the result of the malfunction of the normal appetite regulation loop. An imbalance appears between increased consumption and low energy expenditure, resulting in an accumulation of fat. Given the seriousness of obesity, we focused our study on the influences that 17-β-estradiol could have on the choice of different food categories (lipids, carbohydrates, proteins) through the dopaminergic system in rats. It appears that 17-β-estradiol modulates the activity of the two isoforms of dopamine D2 receptors, which have opposite effects. One of the isoforms would exclusively activate the consumption and metabolism of carbohydrates under the control of 17-β-estradiol, with a balance between energy production and expenditure and resulting in a stabilization of body weight. The other isoform, revealed by sulpiride blockade, would act mainly by hormonal induction of 17-β-estradiol, directing food consumption towards foods with high lipid, protein and carbohydrate potentials. This second isoform of dopamine D2 receptors produces hyperphagia and overweight, which can lead to long-term fat accumulation and obesity. Keywords: 17β-estradiol, D2 receptors, bromocriptine, sulpiride, carbohydrates, lipids, proteins, obesity.