Itch : Associated Response and Antinociception Induced by Intracisternal Endomorphins in Mice

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Author(s)

Abstract

Endomorphin-1 and endomorphin-2 are newly identified endogenous peptides and have high affinity and selectivity for μ-opioid receptors. The present experiments were conducted to determine whether intracisternal injection of these peptides would produce an itch-associated response and antinociception and to compare their effects to that of morphine. Endomorphin-1 and endomorphin-2 (0.3 - 3 nmol/mouse) elicited facial scratching characterized by bell-shaped dose-response curves with a peak effect at endomorphin-1 at 0.3 nmol/mouse and endomorphin-2 at 1 nmol/mouse. Their peak effects were inhibited by subcutaneous pretreatment with naloxone (1 mg/kg). Morphine (0.3 - 30 nmol/mouse) produced facial scratching, and its dose-response curve was also bell-shaped. Scratching of the body trunk, head and ears were not elicited by these doses of endomorphins and morphine. Endomorphin-1 and -2 at doses of 0.3 - 3 nmol/mouse produced dose-dependent antinociception, as measured with the tail-pressure test. The potency and duration of actions of these peptides were comparable to those of morphine. The results suggest that endomorphin-1 and endomorphin-2 are involved in itch-signaling and pain-inhibiting functions of the brain.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 78(3), 337-343, 1998-11-01

    The Japanese Pharmacological Society

References:  25

Cited by:  4

Codes

  • NII Article ID (NAID)
    10008681303
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    4610823
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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