Central Regulation of Urine Production by a Selective μ-Opioid Agonist,[D-Ala^2, N-Me-Phe^4, Gly^5-ol]-Enkephalin, in Rats

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Author(s)

Abstract

We have investigated opioid mechanisms concerning regulation of urine production in the hypothalamic supraoptic nucleus (SON). In this study, the effect of [D-Ala<SUP>2</SUP>, <I>N</I>-Me-Phe<SUP>4</SUP>, G1y<SUP>5</SUP>-ol]enkephalin (DAMGO), a potent selective μ-opioid agonist, microinjected into the SON of anesthetized hydrated rats, on the urine outflow rate was examined. DAMGO caused a dose-dependent decrease in the urine outflow rate with no significant changes in blood pressure nor heart rate. The ED<SUB>50</SUB> value for the antidiuresis was calculated to be 0.055 nmol from the dose-response curve. The antidiuresis elicited by DAMGO (0.1 nmol)was partially inhibited by intra-SON pre-injection of naloxone (3 nmol), a relatively μ-selective opioid antagonist, and timolol (100 nmol), a β-adrenoceptor antagonist, but not by intra-SON pre-injection of phenoxybenzamine (20 nmol), an α-adrenoceptor antagonist, nor atropine (300 nmol), a muscarinic antagonist. Intravenous injection of <I>d</I>(CH<SUB>2</SUB>)<SUB>5</SUB>-D-Tyr(Et)VAVP (16.7 μg), a vasopressin receptor antagonist, did not influence the DAMGO-induced antidiuresis. These findings suggest that antidiuresis mediated through μ-opioid receptors in the SON involves β-adrenoceptors in the nuclei, but does not involve an increase in vasopressin release.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 74(1), 45-49, 1997-05-01

    The Japanese Pharmacological Society

References:  24

Codes

  • NII Article ID (NAID)
    10008678354
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    4219981
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  NDL  J-STAGE 
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