Nicotinic receptors on rat alveolar macrophages dampen ATP-induced increase in cytosolic calcium concentration

Wolfgang Kummer,Petra Hartmann,Katrin S Lips,Simone Biallas,Uwe Pfeil,Sergei A Grando,Veronika Grau,Zbigniew Mikulski

doi:10.1016/j.autneu.2007.06.112

Abstract

Nicotinic acetylcholine receptors (nAChR) have been identified on a variety of cells of the immune system and are generally considered to trigger anti-inflammatory events. In the present study we set out first to determine the nAChR inventory of alveolar macrophages (AM) in the rat, and second to investigate the cellular events evoked by stimulation of AM with nicotine. Rat AM were isolated freshly by bronchoalveolar lavage (BAL). Inter-individually variable expression patterns of nAChR subunits investigated by RT-PCR were noted.

Highlights

Nicotinic acetylcholine receptors have been identified on a variety of cells of the immune system and are generally considered to trigger anti-inflammatory events
Rat alveolar macrophages (AM) are equipped with modulatory Nicotinic acetylcholine receptors (nAChR) with properties distinct from ionotropic nAChR mediating synaptic transmission in the nervous system
Rat alveolar macrophages constitutively express nAChR subunits a9, a10 and b2, but not a7 RT-PCR analysis of mRNA isolated from rat bronchoalveolar lavage (BAL) cells revealed expression of nAChR subunits a2, a3, a5, a9, a10, b1, and b2

Summary

Introduction

Nicotinic acetylcholine receptors (nAChR) have been identified on a variety of cells of the immune system and are generally considered to trigger anti-inflammatory events. It has been demonstrated that TNFa production and release from peritoneal macrophages can be largely inhibited by neurally released ACh thereby attenuating systemic inflammatory responses. This physiological mechanism has been subunit is one of 9 different known ligand-binding a subunits (a1-a7 and a9-a10) that assemble to homoor heteropentamers, partially with additional participation of b subunits, to form a functional nAChR. All these receptors are ligand-gated cation channels, and they are distinct from each other with respect to ligand affinity and to preference for mono- or divalent cations [4]. This allows for selective pharmacological intervention and therapeutic use

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