At least two populations of c-kit positive interstitial cells of Cajal (ICC) lie in thegastric wall, one located at the myenteric plexus level has a pace-making functionand the other located intramuscularly is intermediary in the neurotransmission andregenerates the slow waves. Both of these ICC sub-types express full-lengthdystrophin. Mdx mice, an animal model lacking in full-length dystrophin and usedto study Duchenne muscular dystrophy (DMD), show gastric dismotilities. The aimof the present study was to verify in mdx mice whether: (i) gastric ICC undergomorphological changes, through immunohistochemical and ultrastructural analyses;and (ii) there are alterations in the electrical activity, using intracellularrecording technique. In control mice, ICC sub-types showed heterogeneousultrastructural features, either intramuscularly or at the myenteric plexus level. Inmdx mice, all of the ICC sub-types underwent important changes: coated vesicleswere significantly more numerous and caveolae significantly fewer than in control;moreover, cytoskeleton and smooth endoplasmic reticulum were reduced andmitochondria enlarged. c-Kit-positivity and integrity of the ICC networks weremaintained. In the circular muscle of normal mice slow waves, which consisted ofinitial and secondary components, occurred with a regular frequency. In mdx mice,slow waves occurred in a highly dysrhythmic fashion and they lacked a secondarycomponent. We conclude that the lack of the full-length dystrophin is associatedwith ultrastructural modifications of gastric ICC, most of which can be interpretedas signs of new membrane formation and altered Ca2þ handling, and with defectivegeneration and regeneration of slow wave activity.
|Numero di pagine||17|
|Rivista||Journal of Cellular Physiology|
|Stato di pubblicazione||Published - 2004|
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