A possible role of the plasmalemmal cytoskeleton, nitric oxide synthase, and innervation in infantile hypertrophic pyloric stenosis - A confocal laser scanning microscopic study

In reference to a possible neuropathy in the pathogenesis of infantile hype rtrophic pyloric stenosis (IHPS), previous studies have described alteratio ns in peptidergic transmission while others have recently attributed an imp ortant role to nitrinergic activity. Little attention has been given to the organization of the extracellular matrix (ECM) and the constituent cytoske leton and subsarcolemma of the pyloric smooth-muscle cell. To study a possi ble relationship between neuronal and muscular elements in IHPS, 9 biopsies from patients with IHPS and 5 biopsies of normal pylorus were examined usi ng immunohistochemical techniques with regard to the distribution of nerve cells and fibers (bNOS and PGP 9.5) and the ECM (laminin) and cytoskeleton (talin, vinculin, dystrophin, alpha-smooth iso-actin, desmin) components of the pyloric muscle. Our results showed anti-protein gene product 9.5 and b -nitric oxide synthase immunoreaction respectively reduced or absent in ner ve fibers with a positive reaction inside the ganglion cells. An uneven dis tribution of the ECM component laminin was evident, together with a negativ e immunoreaction to talin and dystrophin. The imunolocalization of vinculin , alpha-smooth iso-actin, and desmin was similar to the controls. Our findi ngs suggest that there is a close relationship between the nerve and muscle elements in the pathophysiology of IHPS and that non-alteration of some el ements of cytoskeleton organization can play an important role in regaining pyloric function after pyloromyotomy.