Effects of Adrenergic and Nitrergic Blockade on Theophylline : Induced Increase in Peripheral Blood Flow in Rat Ear

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Author(s)

Abstract

A bolus injection of theophylline produced a significant increase in peripheral blood flow in anesthetized rat ear, monitored by laser-Doppler flowmetry, with increases in arterial blood pressure and heart rate. These effects were attenuated by previous treatment with reserpine, but reserpine had no effect on the blood flow increase produced by acetylcholine. A dose of propranolol, which caused attenuation of the theophylline-induced increase in heart rate, did not change the peripheral blood flow. The higher dose of propranolol, which nearly canceled the increases in blood pressure and heart rate, caused attenuation of the blood flow increase but did not cancel it. However, the theophylline-induced flow increase was completely reversed by a nitric oxide synthase inhibitor, <I>N</I><SUP>G</SUP>-nitro-L-arginine methyl ester, which alone had no effect, without any change in arterial blood pressure and heart rate. Treatment of the rats with the dose of inhibitor slightly and significantly reduced the response of peripheral blood flow to acetylcholine. The other isomer, <I>N</I><SUP>G</SUP>-nitro-D-arginine methyl ester, and the other inhibitor, <I>N</I><SUP>G</SUP>-monomethyl-L-arginine, did not have such an effect. These results suggest that the flow increase is due to an independent effect on the heart with modification by autonomic reflexes and involves the adrenergic and nitrergic pathways.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 78(3), 345-354, 1998-11-01

    The Japanese Pharmacological Society

References:  31

Codes

  • NII Article ID (NAID)
    10008681329
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    4610824
  • 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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