Effect of cycloheximide on temperature regulation in rats

Area of Science:

• Physiology
• Pharmacology

Background:

• Protein synthesis inhibition is a known effect of cycloheximide.
• Cycloheximide has been reported to have antipyretic properties.

Purpose of the Study:

• To investigate if cycloheximide's antipyretic effect is due to non-specific antimetabolic actions.
• To determine the impact of cycloheximide on thermoregulation and heat production.

Main Methods:

• Administered cycloheximide (5 mg/kg IP) to afebrile female rats at various ambient temperatures (34, 25, 15 degrees C).
• Measured colonic temperature and rate of oxygen consumption (heat production) during cold stress (15 degrees C).
• Compared results with control rats receiving saline.

Main Results:

• Cycloheximide significantly decreased colonic temperature in rats within 60 minutes.
• Cycloheximide administration significantly depressed the increase in oxygen consumption during cold stress.
• Control rats showed an 8.7 ml/min/kg0.75 increase in oxygen consumption, while cycloheximide-treated rats showed only 1.8 ml/min/kg0.75.

Conclusions:

• The data suggest cycloheximide has a general depressant effect on heat production.
• The observed effects indicate cycloheximide may not possess a specific antipyretic effect.
• Thermoregulatory changes during cold stress resemble fever genesis, supporting a general metabolic impact.