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Epidermal growth factor is digested to smaller, less active forms in acidic gastric juice
R J Playford1, T Marchbank, D P Calnan
1Department of Medicine, Royal Postgraduate Medical School, London, England.
Gastroenterology
|January 1, 1995
Summary
Epidermal growth factor (EGF) is less active in acidic gastric juice due to cleavage into smaller forms. Maintaining a higher pH preserves intact EGF, potentially aiding healing processes.
Area of Science:
- Gastroenterology
- Molecular Biology
- Biochemistry
Background:
- Epidermal growth factor (EGF) exhibits potent mitogenic properties and is present in gastric juice.
- The stability of EGF in gastric juice is influenced by physiological and pathophysiological conditions.
Purpose of the Study:
- To examine the stability of epidermal growth factor (EGF) in gastric juice under varying conditions.
- To determine the impact of acid and pepsin on EGF bioactivity.
Main Methods:
- Incubation of recombinant human EGF1-53 with HCl and pepsin.
- Analysis of EGF forms in gastric juice from different patient groups using mass spectrometry and HPLC.
- Assessment of EGF bioactivity via in vitro hepatocyte and in vivo rat stomach assays.
Main Results:
- EGF1-53 was cleaved to EGF1-49 and EGF1-46 in samples with pH < 4 and pepsin.
- Intact EGF proportion increased to ~60% in gastric juice samples with pH > 4.
- Intact EGF1-53 demonstrated 3-4 times greater potency than acid/pepsin-treated EGF.
Conclusions:
- EGF is rapidly cleaved to less active forms in acidic gastric juice.
- Higher pH (> 4) significantly reduces EGF cleavage, preserving its activity.
- This pH-dependent cleavage mechanism may play a role in the healing effects of acid suppressants.
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