6533b86dfe1ef96bd12c9fd3
RESEARCH PRODUCT
Evidence that adenosine is not involved in the non-adrenergic non-cholinergic relaxation in the rat duodenum.
Flavia MulèRosa SerioA. Postorinosubject
AtropineGuanethidinemedicine.medical_specialtyAdenosinePhysiologyDuodenumMuscle RelaxationTetrodotoxinIn Vitro TechniquesBiochemistrychemistry.chemical_compoundTheophyllineInternal medicineIsometric ContractionmedicinePressureAnimalsTheophyllineNeurotransmitterReceptorGuanethidineReceptors PurinergicMuscle SmoothAdenosineAdenosine receptorElectric StimulationRatsAtropineEndocrinologychemistryTetrodotoxinmedicine.drugdescription
In rat isolated duodenal segments, adenosine induced, in the presence of atropine and guanethidine, a dose-dependent, long-lasting (about 20 s), tetrodotoxin (TTX)-resistant relaxation both in endoluminal pressure and in isometric tension. Electrical field stimulation (EFS) induced, in the presence of atropine and guanethidine, a TTX-sensitive short-lasting (about 6 s) relaxation followed by a sustained rebound contraction. Theophylline, a P1 receptor antagonist, at the concentration of 100 microM caused a marked inhibition of the adenosine-induced relaxation, while the EFS-induced relaxation was not modified. Our results suggest that adenosine induces relaxation of the rat duodenal smooth muscle acting on P1 receptors localized at muscular level. However, differences in the morphology and in the sensitivity to theophylline between adenosine- and EFS-induced relaxation ruled out adenosine as neurotransmitter of the non-adrenergic, non-cholinergic inhibitory system.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1990-08-01 | Archives internationales de physiologie et de biochimie |