Effects of repeated caffeine exposure on locomotion induced by fenproporex in adult and adolescent rats

• Grant number: 05/02722-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2005
• End date: July 31, 2006
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Cleopatra da Silva Planeta
• Grantee: Ana Helena Paro
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Psychostimulant drugs are characterized by the fact that they increase psychic and motor activity. This class of drug includes cocaine, amphetamine (and its derivates) and xantines (caffeine, teobromine, and teophiline). Caffeine is the most widely consumed behaviorally active substance in the world. Cocaine and amphetamine are illicit drugs, but, in Brazil, the fenproporex (an amphetamine derivate) is widely used as a licit anoretic drug. There is evidence that the exposure to caffeine can increase the locomotor activating effects of cocaine and amphetamine. Thus, chronic exposure to caffeine could increase the abuse potential of other drugs. Although caffeine and fenproporex are extensively used among the young population, the interaction between these substances has been extensively investigated in adult animals, while a limited number of studies have focused on the consequences of chronic caffeine exposure on amphetamines-induced locomotor activity in animal’s models of adolescence. The aim of the present study is to investigate if the repeated administration of caffeine modifies fenproporex-induced locomotor activity. To evaluate the effect of repeated caffeine on fenproporex-induced locomotor activation, adolescent (P28) or adult (P60) rats will be treated with caffeine (10.0 mg/kg; i.p.) or saline (1ml/Kg; i.p.) for 10 days. Three days after the last injection, animals will receive fenproporex (2.0 mg/kg; i.p.) or saline (1 ml/Kg; i.p.). The locomotor activity will be registered, every 5 minutes, in automatic activity cages during 1 entire hour after injections. (AU)