K. Shibata et al., OVARIECTOMY-INDUCED HYPERALGESIA AND ANTINOCICEPTIVE EFFECT OF ELCATONIN, A SYNTHETIC EEL CALCITONIN, Pharmacology, biochemistry and behavior, 60(2), 1998, pp. 371-376
Using ovariectomized (OVX) rats in the tail-withdrawal nociceptive tes
t, we examined OVX induced hyperalgesia and the antinociceptive effect
of subcutaneously administered elcatonin, a synthetic derivative of e
el calcitonin ([AsU1.7] eel calcitonin). Because tail-withdrawal laten
cy was significantly and continuously reduced and bone mineral density
decreased in OVX rats compared with those of sham-operated rats, it w
as demonstrated that ovariectomy induced prolonged hyperalgesia and os
teoporosis. After repeated administrations for 3 or 4 weeks, subcutane
ously injected elcatonin increased the latency of the OVX rats in a do
se-dependent manner, compared to the vehicle-treated OVX rats. At a do
se of 20 U/kg/day, there were significant differences (p < 0.01) in th
e latency between the elcatonin- and vehicle-treated OVX rats. This ef
fect of elcatonin was completely inhibited by p-chlorophenylalanine tr
eatment, suggesting that the central serotonergic system may be involv
ed in the elcatonin antinociception of OVX-induced hyperalgesia. (C) 1
998 Elsevier Science Inc.