Testosterone affects formalin-induced responses differently in male and female rats.
To evaluate the role of testosterone in pain modulation, we subcutaneously injected male and female rats with testosterone propionate (TP, 5 mg/kg in oil) or oil for 6 days; on the seventh day, all rats were subjected to the formalin test (10%, 50 microl). Behaviours were recorded in an open field (60 min). At the end of the formalin test, the rats were anaesthetized to collect blood from the abdominal aorta. Among the formalin-induced responses, licking was higher in females than males and was decreased by TP in females; jerking and flexing were only slightly affected by treatment. TP increased testosterone plasma levels in both sexes. These results indicate a role of testosterone in modulating formalin-induced responses. The effects appear to be different in males and females.
Aloisi
Anna Maria
AM
Department of Physiology, Section of Neuroscience and Applied Physiology, University of Siena, Via Aldo Moro, 53100 Siena, Italy. aloisi@unisi.it
Ceccarelli
Ilaria
I
Fiorenzani
Paolo
P
De Padova
Anna Maria
AM
Massafra
Cosimo
C
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D005260:Female; D006120:Grooming / Q000187:drug effects / Q000502:physiology; D008297:Male; D010146:Pain / Q000378:metabolism* / Q000503:physiopathology; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013739:Testosterone / Q000097:blood* / Q000494:pharmacology
D013739:Testosterone