Sex-related differences in the analgesic response to the rat tail immersion test.
The analgesic response was evaluated by the tail immersion test in adult male (N = 30), female (N = 21) and androgenized female Wistar rats (N = 15). The reaction time for tail withdrawal from the hot water bath was faster for male than for female rats (3.48 +/- 0.12 vs 6.46 +/- 0.42 s). The reaction time of androgenized female rats was similar to that of male rats (3.08 +/- 0.16 s). Blockade of opiate receptors with naloxone (2 mg/kg, ip) decreased the sensitivity to the noxious stimuli in males (4.08 +/- 0.10 s) and in androgenized females (3.69 +/- 0.19 s) but increased it in female rats (5.01 +/- 0.41 s). These data show sex-related differences in the analgesic response evaluated by the tail immersion test and indicate that administration of androgens to newborn female rats affects their pain sensitivity.
Molina
N
N
Departamento de Ciências Fisiológicas, Faculdade de Odontologia de Araçatuba, Universidade Estadual Paulista, Brasil.
Bedran-de-Castro
M T
MT
Bedran-de-Castro
J C
JC
D000698:Analgesia; D000818:Animals; D005260:Female; D008297:Male; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D012727:Sex Characteristics; D013623:Tail / Q000187:drug effects*; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology
D009270:Naloxone; D013739:Testosterone