Abolition of vagino-cervical stimulation-induced analgesia by capsaicin administered to neonatal, but not adult rats.
We have previously reported that vagino-cervical mechanical stimulation (VS or probing) produces analgesia in rats. Neonatal treatment with capsaicin (CAP) has been shown to reduce the concentrations of several neuropeptides in dorsal root ganglia, spinal cord, and autonomic ganglia, via a neurotoxic effect. In the present study, we report that CAP administered in the neonatal period abolishes the analgesic effect of probing in adulthood. In addition, we report that the ability of VS to potentiate the lordosis response to manual stimulation of the flanks is abolished by neonatal CAP treatment. By contrast, rats treated as adults with CAP show the typical VS-produced effects of analgesia and potentiation of the lordosis response. Our results suggest that neonatal, but not adult, CAP treatment depletes a neuropeptide(s) that mediates the analgesia and lordosis-inducing effects of VS.
Rodriguez-Sierra
J F
JF
Department of Anatomy, University of Nebraska Medical Center, Omaha 68105.
Skofitsch
G
G
Komisaruk
B R
BR
Jacobowitz
D M
DM
D000367:Age Factors; D000698:Analgesia; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001522:Behavior, Animal / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology*; D002584:Cervix Uteri / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D009479:Neuropeptides / Q000502:physiology; D010052:Ovariectomy; D011187:Posture; D051381:Rats; D011919:Rats, Inbred Strains; D014621:Vagina / Q000502:physiology
D009479:Neuropeptides; D004958:Estradiol; D002211:Capsaicin