Effect of mazindol administration on (3H)-N-methylscopolamine binding to rat cerebral cortex

Mazindol has been shown to produce anorexia in several animal species including humans, and its pharmacological effects may be elicited by blockade of neuronal reuptake of dopamine and norepinephrine. Chronic treatment of rats with mazindol (10 mg/kg daily, p.o.) caused an increase in muscarinic receptor density (Bmax = 874.7 femtomoles/mg protein) as compared to controls (Bmax = 629.1 femtomoles/mg protein) in the cerebral motor cortex. An increase in dissociation constant (Kd) values was also observed which changes from 0.57 nM (control) to 1.17 nM after mazindol treatment. The mechanism underlying the observed effect of mazindol on receptors could be related to processes involving other neurotransmitters which also regulate cholinergic activity in the CNS. However, the implications of the eventual dopaminergic control on muscarinic receptors in the cortex is still an open question.