Assiut university
Staff Researches

Involvement of a capsaicin-sensitive TRPV1-independent
mechanism in lipopolysaccharide-induced fever in chickens
Mahmoud, ME., Shimizu, Y., Shiina, T., Nikami, T., Dosoky RM., Ahmed MM., Takewaki, T.

Abstract:
It has been demonstrated that capsaicin blocks lipopolysaccharide (LPS)-induced fever in mammals. In this study, we
investigated TRPV1 (transient receptor potential ion channel of vanilloid subtype-1)-independent action of capsaicin on LPSinduced
fever in chickens. The chicken is a valuable model for this purpose because chicken TRPV1 has been shown to be
insensitive to capsaicin and thus the effects of capsaicin can be attributed to TRPV1-independent mechanisms. Administration
of capsaicin (10 mg/kg, iv) to conscious unrestrained chicks at 5 days of age caused a transient decrease in body temperature.
This effect of capsaicin was not observed in chicks that had been pretreated twice with capsaicin, indicating that the capsaicinsensitive
pathway can be desensitized. LPS (2 mg/kg, ip) induced fever that lasted for about 2.5 h, but fever was not induced in
chicks that had been pretreated with capsaicin for 2 days. The preventive effect of capsaicin on LPS-induced fever was not
blocked by capsazepine, an antagonist for TRPV1, but the antagonist per se blocked the febrile response to LPS. These
findings suggest that a capsaicin-sensitive TRPV1-independent mechanism may be involved in LPS-induced fever.
Published In:
Comparative Biochemistry and Physiology, Part A , Vol. 148, No. 3 , PP. 578–583