Objective The glial cells of the central nervous system are involved in tripartite signaling,therefore we have been investigating the relationship between sensory neurons and non-neuronal cells in isolated preparation...Objective The glial cells of the central nervous system are involved in tripartite signaling,therefore we have been investigating the relationship between sensory neurons and non-neuronal cells in isolated preparations of dorsal root ganglia(DRG).Methods The mixed cell cultures of dissociated DRG cells were separated to yield enriched fractions of IB4-positive cells(small diameter,non-peptidergic cells),IB4-negative cells(small diameter,peptidergic cells,and large diameter cells),and non-neuronal cells(principally satellite glial cells,Schwann cells and fibroblasts).Adenylyl cyclase activity was assayed by measuring production of [3H]cAMP from cells preloaded with [3H]adenine.Results PGE2 and the PGI2 mimetic cicaprost stimulated adenylyl cyclase activity which was inhibited by ONO-AE3-208(EP4 antagonist)or CAY10441(IP antagonist)with estimated pA2 values of 8.9 and 8.2,respectively.Surprisingly,both PGE2 and cicaprost-stimulated [3H] cAMP production was greatest in the non-neuronal cell preparation.Furthermore,when the number of non-neuronal cells was kept constant and the number of neuronal cells was increased,we observed a progressive decrease in prostanoid-stimulated activity.Conclusions Sensory neurons appear to regulate prostanoid receptor-mediated cell signaling in non-neuronal cells within the DRG.展开更多
文摘Objective The glial cells of the central nervous system are involved in tripartite signaling,therefore we have been investigating the relationship between sensory neurons and non-neuronal cells in isolated preparations of dorsal root ganglia(DRG).Methods The mixed cell cultures of dissociated DRG cells were separated to yield enriched fractions of IB4-positive cells(small diameter,non-peptidergic cells),IB4-negative cells(small diameter,peptidergic cells,and large diameter cells),and non-neuronal cells(principally satellite glial cells,Schwann cells and fibroblasts).Adenylyl cyclase activity was assayed by measuring production of [3H]cAMP from cells preloaded with [3H]adenine.Results PGE2 and the PGI2 mimetic cicaprost stimulated adenylyl cyclase activity which was inhibited by ONO-AE3-208(EP4 antagonist)or CAY10441(IP antagonist)with estimated pA2 values of 8.9 and 8.2,respectively.Surprisingly,both PGE2 and cicaprost-stimulated [3H] cAMP production was greatest in the non-neuronal cell preparation.Furthermore,when the number of non-neuronal cells was kept constant and the number of neuronal cells was increased,we observed a progressive decrease in prostanoid-stimulated activity.Conclusions Sensory neurons appear to regulate prostanoid receptor-mediated cell signaling in non-neuronal cells within the DRG.
