Mechanical stimulation increases intracellular XXXX concentration in nodose sensory neurons.

@entity35 @entity593 @entity460 @entity141 @entity2287
The cellular mechanisms involved in activation of mechanosensitive visceral sensory nerves are poorly understood. The major goal of this study was to determine the effect of mechanical stimulation on intracellular @entity460 concentration ([ @entity141 ]i) using nodose sensory neurons grown in culture. Primary cultures of nodose sensory neurons were prepared by enzymatic dispersion from nodose ganglia of 4-8 week old @entity35 . Whole cell [ @entity141 ]i was measured by a microscopic digital image analysis system in @entity593 loaded single neurons. Brief mechanical stimulation of individual nodose sensory neurons was achieved by deformation of the cell surface with a glass micropipette. In 31 of 50 neurons (62%), mechanical stimulation increased [ @entity141 ]i from 125 +/- 8 to 763 +/- 89 nM measured approximately 10 s after stimulation. [ @entity141 ]i then declined gradually, returning to near basal levels over a period of minutes. [ @entity141 ]i failed to increase after mechanical stimulation in the remaining 19 neurons. The mechanically-induced rise in [ @entity141 ]i was essentially abolished after the neurons were incubated for 5-10 min in zero @entity141 buffer (n = 7) or after addition of @entity2287 (10 microM), a blocker of stretch-activated ion channels (n = 5). The effect of @entity2287 was reversed after removal of @entity2287 . The results indicate that: (1) mechanical stretch increases [ @entity141 ]i in a subpopulation of nodose sensory neurons in culture, and (2) the stretch-induced increase in [ @entity141 ]i is dependent on influx of @entity141 from extracellular fluid and is reversibly blocked by @entity2287 . The findings suggest that opening of stretch-activated ion channels in response to mechanical deformation leads to an increase in @entity141 concentration in visceral sensory neurons.(ABSTRACT TRUNCATED AT 250 WORDS)
