Mg. Garry et al., INTRATHECAL INJECTION OF CELL-PERMEABLE ANALOGS OF CYCLIC 3',5'-GUANOSINE MONOPHOSPHATE PRODUCES HYPERALGESIA IN MICE, European journal of pharmacology, 260(2-3), 1994, pp. 129-131
Several recent studies suggest that spinal cord levels of cyclic 3',5'
-guanosine monophosphate (cGMP) may participate in the development of
hyperalgesia. The purpose of this study was to directly evaluate wheth
er cell permeable analogues of cGMP evoke a thermal hyperalgesia (usin
g a hot-plate assay) when administered intrathecally in mice. Our resu
lts indicate that two cell permeable forms of cGMP evoke a dose depend
ent hyperalgesia when administered intrathecally in mice. Additionally
, this hyperalgesia was selective since neither non-cell permeant cGMP
nor guanosine had any effect on the latency of paw withdrawal when co
mpared to the vehicle injected controls. These data indicate that cGMP
is involved in the facilitation of thermal hyperalgesia at the level
of the spinal cord.