Increased expression of transforming growth factor-alpha in infantile hypertrophic pyloric stenosis.
Infantile hypertrophic pyloric stenosis (IHPS) is characterized by hypertrophy of the pyloric muscle. The growth of smooth-muscle cells (SMCs) is regulated by several growth factors. Transforming growth factor-alpha (TGF-alpha) is a growth-regulatory peptide found in a wide range of embryonic and adult tissues. It has been recognized that TGF-alpha has growth-promoting effects in vascular and visceral SMCs. The aim of this study was to investigate whether TGF-alpha plays a role in the pyloric-muscle hypertrophy in IHPS. Full-thickness pyloric-muscle biopsy specimens were obtained at the time of pyloromyotomy from 10 IHPS patients (age range 24-76 days). Age-matched control material included 10 pyloric-muscle specimens taken at autopsy in patients without evidence of gastrointestinal disease. Indirect immunohistochemistry was performed using the ABC method with anti-TGF-alpha polyclonal antibody. In-situ hybridization was performed using a digoxigenin-labelled, TGF-alpha-specific oligonucleotide probe. There was a marked increase in TGF-alpha immunoreactivity and messenger RNA (mRNA) expression in SMCs in pyloric circular and longitudinal muscle in IHPS specimens compared to controls. The increased expression of TGF-alpha mRNA together with increased TGF-alpha immunoreactivity in IHPS suggests increased local synthesis of TGF-alpha by pyloric SMCs, causing pyloric-muscle hypertrophy.
Shima
H
H
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin 12, Ireland.
Puri
P
P
D001706:Biopsy; D006801:Humans; D006984:Hypertrophy; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D009130:Muscle, Smooth / Q000378:metabolism / Q000473:pathology; D011707:Pyloric Stenosis / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D016211:Transforming Growth Factor alpha / Q000096:biosynthesis* / Q000502:physiology
D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha