Flavones isolated from with tracheal smooth muscle relaxant properties.

The inflorescences of are used as folk medicine to treat various respiratory diseases. In this work, we report the isolation of seven known flavones: 5-hydroxy-3,7-dimethoxyflavone , 5,8-dihydroxy-3,7-dimethoxyflavone , 5,7-dihydroxy-3,8-dimethoxyflavone (gnaphaliin A), 3,5-dihydroxy-7,8-dimethoxyflavone (gnaphaliin B), 3,5-dihydroxy-6,7,8-trimethoxyflavone , 3,5,7-trimethoxyflavone and 3--methylquercetin . All these flavones except and showed a relaxant effect on guinea pig tracheal preparation with EC between 69.

Dopamine D and Adenosine A Receptors Interaction on Ca Current Modulation in a Rodent Model of Parkinsonism.

A receptor required previous D receptor activation to modulate Ca currents. Istradefylline decreases pramipexole modulation on Ca currents. Istradefylline reduces A + neurons activity in striatial microcircuit, but pramipexole failed to further reduce neuronal activity.

Calcium currents in striatal fast-spiking interneurons: dopaminergic modulation of Ca1 channels.

Background: Striatal fast-spiking interneurons (FSI) are a subset of GABAergic cells that express calcium-binding protein parvalbumin (PV). They provide feed-forward inhibition to striatal projection neurons (SPNs), receive cortical, thalamic and dopaminergic inputs and are coupled together by electrical and chemical synapses, being important components of the striatal circuitry. It is known that dopamine (DA) depolarizes FSI via D-class DA receptors, but no studies about the ionic mechanism of this action have been reported.

The role of α- and α-adrenoceptor subtypes in the vasopressor responses induced by dihydroergotamine in ritanserin-pretreated pithed rats.

Background: Dihydroergotamine (DHE) is an acute antimigraine agent that displays affinity for dopamine D-like receptors, serotonin 5-HT receptors and α/α-adrenoceptors. Since activation of vascular α/α-adrenoceptors results in systemic vasopressor responses, the purpose of this study was to investigate the specific role of α- and α-adrenoceptors mediating DHE-induced vasopressor responses using several antagonists for these receptors.

Methods: For this purpose, 135 male Wistar rats were pithed and divided into 35 control and 100 pretreated i.

Pharmacological evidence that histamine H3 receptors inhibit the vasodepressor responses by selective stimulation of the rat perivascular sensory CGRPergic outflow.

This study has investigated whether pharmacological activation of Gi/o coupled histamine H3/H4 receptors inhibits the rat vasodepressor sensory outflow. For this purpose, 100 male Wistar rats were pithed, artificially ventilated and pretreated (i.v.