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Preferential Synthesis of Prostaglandin D 2 by Neurons and Prostaglandin E 2 by Fibroblasts and Nonneuronal Cells in Chick Dorsal Root Ganglia
Author(s) -
Vesin MarieFrançoise,
BarakatWalter Ibtissam,
Droz Bernard
Publication year - 1991
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1991.tb02112.x
Subject(s) - prostaglandin e , fibroblast , prostaglandin , dorsal root ganglion , chemistry , microbiology and biotechnology , meninges , embryo , intracellular , biology , biochemistry , medicine , anatomy , dorsum , in vitro , neuroscience
To determine the type and the relative amount of prostaglandins (PGs) synthesized by various neural tissues, homogenates of meninges, dorsal root ganglia (DRG) capsules, decapsulated DRG, and unsheathed sciatic nerves were incubated with [1‐ 14 C]arachidonic acid. Homogenates of cultured cells (meningeal cells, fibroblasts, and nonneuronal or neuronal DRG cells) were used to specify the cells producing particular PGs. The highest synthetic capacity was found in fibroblast‐rich tissues (meninges and DRG capsules) and in cultures of meningeal cells or fibroblasts. Two major cyclooxygenase products were formed: [ 14 C]PGE 2 and an unusual 14 C‐labeled compound, Y. The accumulation of compound Y, corresponding probably to 15‐hydroperoxy PGE 2 , was completely impaired by addition of exogenous GSH, which conversely enhanced the synthesis of [ 14 C]PGE 2 and promoted the formation of [ 14 C]PGD 2 . In contrast, decapsulated DRG or unsheathed sciatic nerves displayed a 10–20 times lower capacity to synthesize PGs than fibroblast‐rich tissues and produced mainly [ 14 C]PGE 2 and [ 14 C]PGD 2 . In this case, [ 14 C]PGE 2 or [ 14 C]PGD 2 synthesis was neither enhanced nor promoted by addition of exogenous GSH. Neuron‐enriched DRG cell cultures allowed us to specify that [ 14 C]PGD 2 is the major prostanoid produced by primary sensory neurons as compared with nonneuronal DRG cells. Because PGD 2 synthesis in DRG and more specifically in DRG neurons does not depend on exogenous GSH and differs from PGD 2 synthesis in fibroblast‐rich tissues, it is concluded that at least two distinct enzymatic processes contribute to PGD 2 formation in the nervous system. Although nonneuronal DRG cells give rise to both PGE 2 and PGD 2 and fibroblasts produce the largest amount of PGE 2 , it should be emphasized that PGD 2 appears as the prostanoid preferentially, although not exclusively, synthesized by primary sensory neurons.