Intravenous alpha-MSH reduces fever in the squirrel monkey

Area of Science:

• Neuroendocrinology
• Immunology
• Primate Physiology

Background:

• Alpha-melanocyte-stimulating hormone (alpha-MSH) has demonstrated antipyretic properties in rabbits.
• The efficacy of alpha-MSH in modulating fever in higher species, particularly primates, remains largely undetermined.

Purpose of the Study:

• To investigate the potential of alpha-MSH as an antipyretic agent in a primate model.
• To determine if alpha-MSH can reduce fever induced by bacterial endotoxins in squirrel monkeys.

Main Methods:

• Squirrel monkeys were utilized as a primate model due to their reliable fever response to bacterial endotoxins.
• Endotoxin was administered intravenously, and alpha-MSH was administered following a 0.3°C increase in rectal temperature.
• Dose-response relationships for endotoxin and alpha-MSH were established in pilot studies.

Main Results:

• Alpha-MSH administration (100-400 micrograms) significantly reduced the area under the fever curve by an average of 50.0%.
• Alpha-MSH did not affect normal body temperature in afebrile states.
• Molar equivalent doses of acetaminophen showed minimal effect on endotoxin-induced fever.

Conclusions:

• Alpha-MSH exhibits significant antipyretic effects in squirrel monkeys, supporting its role in fever regulation.
• These findings suggest that alpha-MSH may be a key central modulator of fever in primates, similar to its role in rabbits.
• Alpha-MSH's efficacy in primates warrants further investigation for potential therapeutic applications in fever management.