Effects of Imipramine, an Uptake Inhibitor, on Double-Peaked Constrictor Responses to Periarterial Nerve Stimulation in Isolated, Per fused Canine Splenic Arteries

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Author(s)

Abstract

Using a cannula insertion method, periarterial nerve electrical stimulations were performed at 1 and 10 Hz in the isolated, perfused canine splenic artery. Electrical nerve stimulation readily caused double-peaked vasoconstrictions. The 1st-peak response at 1 Hz was not influenced by treatment with imipramine but the 2nd one was significantly enhanced by it. The 2nd-peak response was markedly blocked by prazosin. An additional treatment with α, β-methylene ATP, a P2X-purinoceptor desensitizer, abolished electrical stimulation-induced vascular responses that remained. At 10 Hz, the responses to electrical stimulation were not significantly influenced by imipramine. On the other hand, the imipramine treatment inhibited the tyramine-induced vasoconstriction but potentiated the noradrenaline-induced one. ATP-induced responses were not modified by imipramine. From these results, it is concluded that 1) the 1st-peaked constriction is mainly due to a P2X-purinoceptor-dependent mechanism, 2) the 2nd one is mainly due to an α<SUB>1</SUB>-adrenoceptor-dependent mechanism, and 3) presynaptic uptake mechanisms may perform an important role in the regulation of vascular reactivity, especially at a low frequency.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 79(4), 461-466, 1999-04-01

    The Japanese Pharmacological Society

References:  24

Cited by:  6

Codes

  • NII Article ID (NAID)
    10008683533
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    4706115
  • 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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