Dissociation of Potentiation of Leu31 Pro34 Neuropeptide Y on Adrenergic and Purinergic Transmission in Isolated Canine Splenic Artery

[摘要] References(47)Cited-By(8)The present study observed the effects of an activation of neuropeptide Y(NPY)Y1 receptors on adrenergic and purinergic components of double−peaked vasoconstrictor responses to periarterial nerve stimulation in the isolated, perfused canine splenic arteries.The results showed that 3−30 nM Leu31 Pro34 neuropeptide Y(LP−NPY)produced a dose−dependent potentiation of double−peaked vasoconstrictor responses to trains of 30−s pulses at 1, 4 or 10 Hz of stimulation.The potentiation of LP−NPY of the nerve−stimulated vasoconstrictions were completely inhibited by subsequent blockade of α1−adrenoceptors or Y1 receptors with 0.1μM prazosin or with 1μM BIBP 3226((R)−N2−(diphenylacetyl)−N−[(4−hydroxyphenyl)methyl]−argininamide), respectively.The remaining responses in the presence of LP−NPY and prazosin were abolished by P2X receptor desensitization with 1μM α, β−methylene ATP.Moreover, 30 nM LP−NPY failed to modify the vasoconstrictor responses to nerve stimulation after treatment with prazosin.A subsequent administration of α, β−methylene ATP completely suppressed the remaining responses after prazosin and LP−NPY.The vasoconstrictions induced by 0.003−1 nmol noradrenaline and 0.003−1μmol ATP were slightly, but not significantly enhanced by 30 nM LP−NPY.The observations indicated that activation of postjunctional NPY Y1 receptors may have an important role in the modulation of adrenergic rather than purinergic transmission of the sympathetic co−transmission.

[学科分类] 药理学

[关键词] Leu31 Pro34 neuropeptide Y;NPY Y1 receptor antagonist;BIBP 3226;Sympathetic nerve stimulation;Splenic artery