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alpha-MSH injected into the septal region reduces fever in rabbits
Abstract:
In previous research the concentration of alpha-MSH within the septal region of rabbits increased with fever. This finding raises the possibility that the septal concentration of this peptide, which reduces fever when given both peripherally and intracerebroventricularly, is important to limitation of fever. To test this idea, rabbits with cannulas in the septal region were made febrile by IV injections of leukocytic pyrogen (LP). Injection of alpha-MSH (1 microgram bilaterally) into the septal region did reduce fever, consistent with the idea that the increase in septal alpha-MSH concentration which occurs naturally in fever limits the febrile response. We also noted late rises in body temperature when experimental and control septal injections were given close together in time. These increases in temperature were similar to those known to occur after injections into the primary temperature control in the PO/AH region. This commonality further strengthens the possibility that septal neurons are important to central modulation of body temperature.
Insights
Alpha-melanocyte-stimulating hormone (alpha-MSH) in the rabbit septal region helps limit fever. Septal alpha-MSH injections reduced fever, supporting its natural role in temperature regulation.
Area of Science:
- Neuroscience
- Physiology
- Endocrinology
Background:
- Previous studies observed elevated alpha-MSH concentrations in the septal region during fever in rabbits.
- Alpha-MSH is known to reduce fever when administered peripherally or intracerebroventricularly.
Purpose of the Study:
- To investigate the role of septal alpha-MSH in fever limitation.
- To determine if endogenous septal alpha-MSH concentration naturally limits the febrile response.
Main Methods:
- Rabbits were induced into a febrile state using intravenous injections of leukocytic pyrogen (LP).
- Alpha-MSH (1 microgram bilaterally) was injected into the septal region of febrile rabbits.
- Body temperature changes were monitored following septal injections.
Main Results:
- Septal alpha-MSH injections significantly reduced fever in rabbits.
- This reduction supports the hypothesis that naturally increased septal alpha-MSH limits fever.
- Late temperature increases, similar to those seen with PO/AH region stimulation, were observed with septal injections.
Conclusions:
- The septal concentration of alpha-MSH plays a crucial role in limiting the febrile response.
- Septal neurons are implicated in the central modulation of body temperature.
- Findings suggest a physiological mechanism for fever regulation involving the septal region.