脊髄におけるプロスタグランジン (特集 神経研究の最近の知見--基礎と臨床から)  [in Japanese] Prostaglandins in spinal cord : enzymological and histological study of prostaglandin F synthase  [in Japanese]

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Abstract

In the spinal cord, prostaglandins participate in the pain transmission including hyperalgesia and allodynia. Prostaglandin D2 and E2 induce hyperalgesia, while prostaglandin E2 and F2α induce allodynia. PGF2α synthase (PGFS) produce two stereoisomers of PGF2, PGF2α and9α, 11β-PGF2 which are synthesized from PGH2 and PGD2, respectively, by the distinct reductions in the prostaglandin synthesis pathway. Because the two reduction are occurred in the different active sites, PGFS is a multifunctional enzyme. PGFS has at least two isozymes, namely, PGFSⅠ and Ⅱ with different Km values for PGD2 (120 and 10μM, respectively). They belong to the aldo-keto reductase superfamily based on substrate specificity, molecular weight, and amino acid sequence. In vivo, PGFSs possibly reduce some steroids such as dihydrotestosterone and dihydroprogesterone by their enzymological characteristic. The morphological study of PGFSⅠ and Ⅱ in the rat spinal cord demonstrated their distinct localization. That is, PGFSⅠ existed in neuronal somata and dendrites, and PGFSⅡ existed in ependymal cells and tanycytes surrounding the central canal. Additionally, both PGFSⅠ and Ⅱ existed in endothelial cells of blood vessels. Furthermore, PGF2α receptor, namely FP, was also present in neuronal somata and dendrites. Immunoreactivity for PGFSⅠ and FP was relatively intense in the dorsal horn of the spinal cord that is a connection site of pain transmission. PGFSⅡ in the ependymal cells and tanycytes is not co-localized with FP, and may mainly metabolize PGD2 which is one of the sleep inducers and abundant in the cerebrospinal fluid. These findings suggest that PGFSⅠ and Ⅱ in the rat spinal cord has different biological actions such as neuronal active receptivity and fluid component control, via different cell groups.

Journal

  • Shikoku acta medica

    Shikoku acta medica 61(1・2), 25-30, 2005-04-25

    徳島医学会

Codes

  • NII Article ID (NAID)
    40006794080
  • NII NACSIS-CAT ID (NCID)
    AN00102041
  • Text Lang
    JPN
  • Article Type
    特集
  • Journal Type
    大学紀要
  • ISSN
    00373699
  • NDL Article ID
    7379419
  • NDL Source Classification
    ZS7(科学技術--医学)
  • NDL Call No.
    Z19-344
  • Data Source
    NDL  IR 
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