In vitro Measurements of Tracheal Constriction Using Mice

摘要: Transgenic and knockout mice have been powerful tools for the investigation of physiology pathophysiology airways1,2. In vitro tensometry isolated tracheal preparations has proven to be a useful assay airway smooth muscle (ASM) contractile response in genetically modified mice. These are relatively simple, provide robust response, retain both functional cholinergic nerve endings responses, even after long incubations. Tracheal also provides study variety second messenger signaling pathways that affect contraction muscle. Contraction trachea is primarily mediated by parasympathetic, nerves release acetylcholine onto ASM (Figure 1). The major receptors muscarinic M2 M3 which Gi/o Gq coupled receptors, respectively3,4,5. evoke coupling activate phospholipase C, increase IP3 production IP3-mediated calcium from sarcoplasmic reticulum3,6,7. M2/Gi/o believed enhance contractions inhibition adenylate cyclase leading decrease cAMP levels5,8,9,10. constitute so called "pharmaco-contraction coupling" muscle11. addition, through (and modulated signaling) involves depolarize turn L-type, voltage-dependent channels 1) influx (so "excitation-contraction coupling")4,7. More detailed reviews on controlling constriction can found4,12. above appear conserved between other species. However, mouse tracheas differ species some pathways. Most prominent their lack histamine adenosine13,14, well-known modulators humans species5,15. Here we present protocols isolation murine rings measurement output. Included descriptions equipment configuration, ring measurements. Examples given evoking indirectly using high potassium stimulation directly depolarization (1. K+, Figure methods presented stimulations alone electric field (2. EFS, 1), or direct exogenous neurotransmitter applied bath (3. ACH, This flexibility ease preparation renders model number cascades involved contraction.