Effects of Dopamine Administration on Anxiety in Male Rat

Background: Abstract Anxiety is a common disease in the society. Several neurotransmitters. The aim of this study was to investigate indirect effect of dopamine on anxiety in rat. Methods: In this experimental study, eight male rats were divided into control and experimental groups. The control group received saline and the tested groups received different IP doses of drugs haloperidol (dopamine receptor antagonist), SKF38393 (dopamineD1 receptor agonist) and quinpirol (dopamine D2receptor agonist). For studying of anxiety-like and antianxiety effects Vogels conflict test and Elevate plus-maze (EP-M) test were used. Findings: Injection of different doses of haloperidol in rats could increase the number of times of passing through place of received shock by apparatus in comparison with control group in Vogels test. In EP-M test, injection of 0.04 mg/kg of haloperidol increased the number of entrance to open arm and time spent on arm comparing to the control group. Quinpirol diminished the number of times of passing through place of receiving shock in comparison with control group in Vogels test. In EP-M test in dose 1 mg/kg number of entrance to open arm and the time spent on arm decreased comparing to the control group. Conclusion: The findings of this study showed that by increasing the doses of haloperidol, the effect of this antagonist has been significant and diminished anxiety. The SKF38393 and Quinpirol by occupying their own dopamine receptor D1, D2 had an effect like endogenous dopamine and made the rats anxious. Key words: Dopamine, Vogel’s conflict test, EP-M test, antagonist, D1and D2 receptor agonist