CARRAGEENAN-INDUCED INFLAMMATION ALTERS THE CONTENT OF I-CGMP AND I-CAMP IN THE DORSAL HORN OF THE SPINAL-CORD

Hindpaw injections of carrageenan (CARRA) decreased paw withdrawal latencies to radiant heat and increased hindpaw edema. At the peak of hyperalgesia, the content of immunoreactive guanosine 3',5'-cyclic monophosphate (i-cGMP) was increased, while immunoreactive adenosine 3',5'-cyclic monophosphate (i-cAMP) was decreased in lumbar, but not cervical dorsal horn. In general, the content of i-cGMP in the dorsal horn was correlated with thermal hyperalgesia throughout the course of this model. These results indicate that a peripheral inflammation alters the content of i-cGMP and i-cAMP in the spinal cord and, further, suggest that these nucleotides are involved in the modulation of hyperalgesia in the spinal cord.