c-Kit immunoreactive interstitial cells in the human gastrointestinal tract

Area of Science:

• Gastroenterology
• Cell Biology
• Histology

Background:

• c-Kit immunopositive cells are vital for gastrointestinal (GI) motility, acting as pacemakers and neurotransmission mediators.
• These cells are identified as interstitial cells of Cajal (ICs) in mice, but their distribution and characteristics in humans are not fully understood.

Purpose of the Study:

• To investigate the distribution and ultrastructure of c-Kit immunopositive cells in the normal human GI tract.
• To classify these cells morphologically and determine their relationship with interstitial cells of Cajal (ICs).

Main Methods:

• Analysis of 39 human GI tissue samples from esophagus to sigmoid colon.
• Utilized immunohistochemistry, electron microscopy, and immuno-electron microscopy.
• Examined tissues from fetal to adult ages, excluding individuals with motility disorders.

Main Results:

• c-Kit positive cells were found in the external muscle layer throughout the esophagus to the sigmoid colon.
• Two distinct morphological groups were identified: spindle-shaped cells (esophagus, stomach, small intestine) and multipolar/bipolar cells (colon).
• Ultrastructural analysis revealed differences in intermediate filaments and endoplasmic reticulum between the two groups, with both showing caveolae.

Conclusions:

• The study clarifies the distribution and classification of c-Kit immunopositive cells in the human GI tract.
• While these cells largely correspond to ICs, some ICs may not express c-Kit.
• Findings provide a foundation for understanding GI pacemaking and neurotransmission in humans.