Dopamine influences the mesolimbic circuitry to regulate food intake. It may modulate the reward aspect of eating like the cannabinoids. Brain Res Brain Res Rev. 1998 Dec;28(3):309-69. Five dopamine receptors have been described D1-D5. Agonists to D1 and D5 receptors (eg: Apomorphine) decrease the frequency of feeding while D2 agonists (eg: Bromocriptine) reduce the rate of eating. On the other hand, D1 antagonism ( eg: Sulpride) increases food intake. Dopamine D2 receptors are decreased in obese individual in proportion to their BMI. Lancet. 2001 Feb 3;357(9253):354-7.
Exercise can increase dopamine release Brain Res Bull. 1994;35(1):41-9. with increased number of D2 receptors, Psychopharmacology (Berl). 1987;92(2):236-40. thus facilitating weight loss. ob/ob mice treated with dopamine agonists show normalisation of weight. Neuroendocrinology. 2000 Jan;71(1):68-78. In fact, any modality that increases extra cellular dopamine (amphetamine, methylphenidate, cocaine) can produce appetite suppression. Pharmacol Biochem Behav. 1988 Jul;30(3):641-8. On the other hand drugs that block dopamine D2 receptors increase appetite with resultant weight gain. Acta Psychiatr Scand.1999 Jul;100(1):3-16.
Exercise can increase dopamine release Brain Res Bull. 1994;35(1):41-9. with increased number of D2 receptors, Psychopharmacology (Berl). 1987;92(2):236-40. thus facilitating weight loss. ob/ob mice treated with dopamine agonists show normalisation of weight. Neuroendocrinology. 2000 Jan;71(1):68-78. In fact, any modality that increases extra cellular dopamine (amphetamine, methylphenidate, cocaine) can produce appetite suppression. Pharmacol Biochem Behav. 1988 Jul;30(3):641-8. On the other hand drugs that block dopamine D2 receptors increase appetite with resultant weight gain. Acta Psychiatr Scand.1999 Jul;100(1):3-16.