The Effects of Dopamine Antagonists on Sham and Real Feeding of Sucrose Solutions: Are Peripheral Dopamine Receptors Implicated?

Abstract

The present thesis examined the relative contribution of dopamine (DA) receptors in the brain and periphery in the control of sucrose intake. Intraperitoneal (ip) administration of pimozide, an antagonist at peripheral and brain DA receptors, suppressed both sham and real sucrose intake in a dose-related manner. In contrast, ip injections of the peripheral DA antagonist domperidone affected neither sham nor real sucrose intake. The inability of domperidone to influence sucrose intake did not result from a lack of biological activity because doses of domperidone that did not alter sucrose intake significantly inhibited gastric acid secretion. The results indicate that central, but not peripheral DA receptors are involved in the control of feeding of sucrose solutions and that sham sucrose intake appears to be more sensitive to disruption of DA activity than real sucrose intake.