EMAIL THIS PAGE TO A FRIEND

The Journal of membrane biology

Serotonergic agonists inhibit calcium-activated potassium and voltage-dependent sodium currents in rat taste receptor cells.


PMID 10630928

Abstract

Recently we reported that rat taste receptor cells respond to the neurotransmitter serotonin with an inhibition of a calcium-activated potassium current [17]. In the present study, this observation is confirmed and extended by studying the effects of an array of serotonergic agonists on membrane properties, calcium-activated potassium current, and voltage-dependent sodium current in taste receptor cells using the patch-clamp recording technique in the whole-cell configuration. Serotonergic inhibition of calcium-activated potassium current was mimicked by the agonists N-(3-trifluoromethylphenyl)piperazine and by (+/-)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene. Both produced reversible inhibition of K(Ca) as well as significantly increasing the input resistance of the cell. The agonists 1-(1-naphthyl)piperazine and buspirone (both serotonin receptor 1A agonists) were similarly effective in reducing K(Ca). Outward current was unaffected by application of phenylbiguanide, a serotonin receptor 3 agonist, though current was affected by subsequent application of (+/-)-2-dipropylamino-8-hydroxy-1,2,3, 4-tetrahydronaphthalene. Two agonists-N-(3-trifluoromethylphenyl)piperazine and (+/-)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene-were also tested on voltage-dependent sodium currents; both were effective and reversible in reducing its magnitude at a variety of applied potentials. These data are consistent with the notion that serotonin effects in rat taste receptor cells are mediated by serotonin 1A receptors, though other receptor subtypes may be additionally expressed. Serotonin may affect the taste cell electrical properties during active stimulation in a paracrine fashion.

Related Materials

Product #

Image

Description

Molecular Formula

Add to Cart

S003
1-(1-Naphthyl)piperazine hydrochloride, needles
C14H16N2 · HCl