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Neuroeffector actions of thromboxane B 2 in dog isolated mesenteric arteries
Author(s) -
Okamura Tomio,
Nakajima Masatoshi,
Toda Noboru
Publication year - 1988
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1988.tb11443.x
Subject(s) - neuroeffector , medicine , endocrinology , mesenteric arteries , long term potentiation , thromboxane , stimulation , antagonist , receptor antagonist , thromboxane a2 , chemistry , methysergide , prostaglandin , norepinephrine , receptor , platelet , artery , dopamine
1 Thromboxane (TX) B 2 and epithiomethano (sTXA 2 ), in concentrations that were insufficient to alter the basal tone, potentiated contractile responses of helical strips of dog mesenteric arteries to transmural electrical stimulation. The potentiating effect of TXB 2 (up to 10 −6 m ) was not abolished by diphloretin phosphate (DPP), a prostaglandin antagonist, whereas the potentiation by sTXA 2 was abolished by the antagonist. 2 sTXA 2 and TXB 2 (3 × 10 −6 m or higher) potentiated the responses to noradrenaline, the potentiation being antagonized by DPP. 3 3 H‐overflow evoked by transmural stimulation in superfused arterial strips previously soaked in medium containing [ 3 H]‐noradrenaline was increased by TXB 2 , but not altered by sTXA 2 . 4 TXB 2 in low concentrations potentiated the contractile response to adrenergic nerve stimulation, possibly by increasing the release of noradrenaline, while the potentiation by the TXA 2 analogue appears to be due to increased sensitivity of the arteries to noradrenaline. Prejunctional effects of TXB 2 may be mediated by receptor sites functionally different from those located postjunctionally.