Control of transmitter release in guinea-pig vas deferens by prejunctional P1-purinoceptors
| Autor: | Geoffrey Burnstock, Lorna A. Meldrum, Peter Sneddon |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Male
Agonist medicine.medical_specialty Adenosine 2-Chloroadenosine medicine.drug_class Guinea Pigs In Vitro Techniques Biology Inhibitory postsynaptic potential Norepinephrine chemistry.chemical_compound Adenosine Triphosphate Vas Deferens Theophylline Internal medicine medicine Animals Neurotransmitter Pharmacology Membrane potential Neurotransmitter Agents Adenine Purinergic receptor Receptors Purinergic Vas deferens Dipyridamole Electric Stimulation Receptors Neurotransmitter medicine.anatomical_structure Endocrinology chemistry Excitatory postsynaptic potential Muscle Contraction medicine.drug |
| Zdroj: | European Journal of Pharmacology. 105:293-299 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/0014-2999(84)90621-6 |
| Popis: | The specific P 1 -purinoceptor agonist 2-chloroadenosine (3 × 10 −7 M to 3 × 10 −6 M) reduced the magnitude of excitatory junction potentials (e.j.p.s) recorded from guinea-pig vas deferens in response to field stimulation of the sympathetic nerves, but did not have any direct effect on the resting membrane potential. Trains of pulses (2–16 Hz) for 20 s produced a biphasis contractile response, both phases of which were reduced by 2-chloroadenosine (10 −7 to 10 −5 M) by up to 45%. In contrast, the same concentration of 2-chloroadenosine enhanced by about 20% the contractile response of the vas deferens to exogenously applied adenosine 5′-triphosphate (ATP) and noradrenaline (NA). The specific P 1 -purinoceptor antagonist 8-phenyltheophylline (8-PT) reversed the inhibitory effect of 2-chloroadenosine on e.j.p. magnitude, partially reversed the inhibitory action of 2-chloroadenosine on both phases of the contractile response to nerve stimulation, and partially reversed the enhancing effect of 2-chloroadenosine on responses to exogenous ATP and NA. We propose that release of ATP and NA (as cotransmitters) from sympathetic nerves can be modulated by prejunctional P 1 -purinoceptors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|