Intrathecal CGRP(8-37) results in a bilateral increase in hindpaw withdrawal latency in rats with a unilateral thermal injury.
Neuropeptides
; 31(6): 601-7, 1997 Dec.
Article
en En
| MEDLINE
| ID: mdl-9574827
ABSTRACT
The present study was performed to explore the effects of intrathecal administration of calcitonin gene-related peptide8-37 (CGRP(8-37)) on the hindpaw withdrawal latency (HWL) to pressure in rats with one thermally injured hindpaw. Furthermore, the interaction of CGRP(8-37)and naloxone was studied. Thermal injury was performed by dipping the left paw into 60 degrees C for 20 s. This induced a significant increase in the volume of the left hindpaw (P<0.001) and significant bilateral decreases of the latency of hindpaw withdrawal response to mechanical stimulation (Left P<0.001; right P<0.05). Intrathecal administration of 10, 20 and 40 nmol of CGRP(8-37), but not of 1 or 5 nmol, induced a significant bilateral increase in HWLs (P<0.001). The effect of CGRP(8-37) was partly reversed by intrathecal injection of naloxone at a dose of 32 and 64 microg respectively. Using radioimmunoassay, we found a significant bilateral increase in the concentration of CGRP-like immunoreactivity in the perfusate of both hindpaws 24 h after unilateral thermal injury (left P< 0.001; right P< 0.05). There was also an increase in the amount of CGRP-like immunoreactivity in the cerebrospinal fluid (P< 0.001), but not in plasma. The results indicate that CGRP plays a role in the transmission of nociceptive information in the spinal cord of thermally injured rats. Furthermore, our findings suggest that opioids can modulate CGRP-related effects in the spinal cord.
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Bases de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
/
Tiempo de Reacción
/
Reflejo
/
Quemaduras
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Péptido Relacionado con Gen de Calcitonina
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Mióticos
Límite:
Animals
Idioma:
En
Revista:
Neuropeptides
Año:
1997
Tipo del documento:
Article
País de afiliación:
Suecia