Time-dependent changes in Bolton-Hunter-labeled 125I-substance P binding in rat spinal cord following unilateral adjuvant-induced peripheral inflammation.
Time-dependent changes in Bolton-Hunter-labeled 125I-substance P binding occurred in the dorsal horn of the spinal cord following unilateral adjuvant-induced inflammation in the hindpaw of the rat. Inflammation was characterized by measures of edema and hyperalgesia. Edema and hyperalgesia were both present 6 h after induction of inflammation. However, by eight days, hyperalgesia had dissipated while edema persisted. Six hours after the induction of inflammation, widespread decreases in Bolton-Hunter-labeled 125I-substance P binding occurred on both sides of the dorsal horn of spinal level L4 in comparison to the control group. However, by two days, widespread increases in Bolton-Hunter-labeled 125I-substance P binding occurred on both sides of the spinal cord at level L4 compared to the control group. The increase in radioligand binding was primarily due to a 10-fold increase in affinity of neurokinin-1 receptors for substance P. At later time-points of four and eight days, Bolton-Hunter-labeled 125I-substance P binding remained increased only in laminae I/II on the side of the spinal cord ipsilateral to inflammation. The changes in Bolton-Hunter-labeled 125I-substance P binding suggest that alterations in substance P synaptic transmission in the spinal cord may contribute to the increased excitability of spinal neurons that accompanies adjuvant-induced peripheral inflammation.
Stucky
C L
CL
Graduate Program in Neuroscience, University of Minnesota, Minneapolis 55455.
Galeazza
M T
MT
Seybold
V S
VS
D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism* / Q000473:pathology; D001345:Autoradiography; D004487:Edema / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology; D010146:Pain / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*; D013388:Succinimides / Q000378:metabolism*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
C043194:Bolton Hunter reagent-substance P conjugate; D007457:Iodine Radioisotopes; D013388:Succinimides; D013373:Substance P