Sauvagine: effects on thermoregulation in the rat

Area of Science:

• Neuroendocrinology
• Comparative Physiology
• Thermoregulation

Background:

• Sauvagine is a 40 amino acid peptide from the skin of the South American frog Phyllomedusa sauvagei.
• It is structurally related to mammalian corticotropin-releasing factor (CRF).

Purpose of the Study:

• To investigate the thermoregulatory effects of sauvagine in rats.
• To determine if the pituitary-adrenal axis mediates sauvagine-induced hypothermia.
• To assess the role of CRF and its antagonist in sauvagine's thermoregulatory actions.

Main Methods:

• Administration of sauvagine (centrally or peripherally) to rats at different ambient temperatures (+4°C, +22°C, +34°C).
• Thermoregulatory response assessment in hypophysectomized, adrenalectomized, and sham-operated rats.
• Administration of CRF and a CRF receptor antagonist (alpha-helical CRF (9-41)).

Main Results:

• Sauvagine induced dose-dependent hypothermia in rats at +4°C and +22°C, but not at +34°C.
• Hypothermia occurred in hypophysectomized, adrenalectomized, and sham-operated rats, indicating the pituitary-adrenal axis is not involved.
• CRF had no effect on thermoregulation, and the CRF antagonist did not alter the hypothermic response to sauvagine.

Conclusions:

• Sauvagine-induced hypothermia in rats is independent of the pituitary-adrenal axis.
• The thermoregulatory effects of sauvagine are not mediated by corticotropin-releasing factor (CRF) pathways.