Studies on food intake in the fasted rat

Area of Science:

• Pharmacology
• Neuroscience
• Behavioral Science

Background:

• Investigating the efficacy of anorexigenic agents is crucial for understanding appetite regulation.
• Comparing different routes of drug administration provides insights into pharmacokinetic and pharmacodynamic differences.

Purpose of the Study:

• To compare the anorexigenic effects of orally and intravenously administered d-amphetamine sulfate, fenfluramine hydrochloride, and cocaine hydrochloride in fasted rats.
• To evaluate the dose-dependent effects and duration of action of various anorexigenic agents, including quipazine maleate and mazindol, as well as the contrasting effects of diazepam.

Main Methods:

• Rats were fasted and administered various drugs orally or intravenously.
• Food intake was measured over a 4-hour period post-drug administration.
• ED50 values (effective dose for 50% suppression) were calculated for anorexigenic effects.

Main Results:

• Intravenous administration showed lower ED50 values for d-amphetamine, fenfluramine, and cocaine in the first hour compared to oral administration.
• Dose-dependent anorexigenic effects of d-amphetamine, fenfluramine, and cocaine were observed only with oral administration over 4 hours.
• Mazindol exhibited a sustained anorexigenic effect, evident the day after administration, while diazepam showed biphasic effects on food intake.

Conclusions:

• Oral administration is a more effective route for eliciting anorexigenic effects from d-amphetamine, fenfluramine, and cocaine in rats.
• The tested rat model is suitable for further research into anorexigenic agents and minor tranquilizers.
• Mazindol demonstrates a prolonged anorexigenic impact, suggesting potential for sustained appetite suppression.