Brief Report
Copyright ©The Author(s) 1997. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 15, 1997; 3(4): 245-245
Published online Dec 15, 1997. doi: 10.3748/wjg.v3.i4.245
Radioimmunoassay-detected basal level of epidermal growth factor in gastric juice of 86 healthy Chinese volunteers
Li Zhang, Ming-Liang Zhang, Yue-Qing Yan, Da-Xing Liang
Li Zhang, Ming-Liang Zhang, Yue-Qing Yan, Da-Xing Liang, Department of Digestive Research, Second Affiliated Hospital of Hengyang Medical College, Hengyang 421001, Hunan Province, China
Li Zhang, female, born on July 12, 1964 in Yongxing County, Hunan Province, graduated from the Department of Medicine in Hengyang Medical College, currently Physician in Charge engaged in the diagnostic and therapeutic study of Helicobacter pylori infection, having 7 papers published.
Author contributions: All authors contributed equally to the work.
Supported by The Health and Scientific Foundation of Hunan Province, No. 93015.
Correspondence to: Dr. Li Zhang, Department of Digestive Research, Second Affiliated Hospital of Hengyang Medical College, Hengyang 421001, Hunan Province, China
Telephone: +86-734-8223251-8405
Received: October 10, 1996
Revised: November 10, 1996
Accepted: June 28, 1997
Published online: December 15, 1997

Abstract
Key Words: Gastric juice, Epidermal growth factor analysis, Radioimmunoassay



INTRODUCTION

Epidermal growth factor (EGF) is a low molecular weight polypeptide consisting of 53 amino acid residues[1]. EGF is primarily produced by the submaxillary glands and Brunner’s glands, but its distribution pattern spans the gastrointestinal tract with a particularly high concentration in gastric juice. To date, however, the precise quantitative value of EGF in gastric juice of healthy subjects has not been reported for a study cohort of Chinese. In the study presented herein, we used radioimmunoassay (RIA) to measure the basal level of EGF in 86 healthy Chinese volunteers of various age.

MATERIALS AND METHODS
Subjects

Eighty-six healthy volunteers, including 24 children (male/female, 18/6; age range: 8-9 years) 28 young adults (male/female, 16/12; age range: 18-20 years) and 34 adults over the age of 40 (male/female, 20/14).

Methods

Special capsules designed for collecting minute quantities of gastric juice were swallowed by each of the 86 subjects under basal condition (i.e. before 8 am in the morning, representing the fasting state). After 20 min in the stomach, the capsules were manually extracted; the volume of gastric juice in each ranged from 0.3 mL to 0.5 mL. Each specimen was preserved individually by freezing at -40 °C until use. In preparation for measurement and analysis, the specimen was centrifuged at 2000 r for 30 min at 4 °C. A total of 0.1 mL of the resulting supernatant was used to measure EGF by RIA, according to the method described by Lu et al[2].

RESULTS

The average EGF concentration in the gastric juice of the 86 healthy volunteers under basal condition was 0.62 ± 0.15 μg/L. The values of EGF by age group were as follows: Children, 0.61 ± 0.14 μg/L; young adults, 0.65 ± 0.14 μg/L; older adults, 0.59 ± 0.13 μg/L. The EGF level among males in the study (n = 52) was 0.61 ± 0.14 μg/L and among females was 0.62 ± 0.15 μg/L. No statistically significant differences were noted between the different age and sex groups.

DISCUSSION

The primary sources of EGF are the submaxillary glands and Brunner’s glands of the duodenum. It is believed that EGF can inhibit secretion of gastric acid and stimulate DNA synthesis, and that it plays a role in protection of gastrointestinal mucosa[3]. Although, EGF is known to be of higher concentration in the gastric juice, the exact concentration of EGF in normal gastric juice had not yet been defined, partially due to the inconvenience of collecting specimens. Conventional gastric tubing and gastroscopy causes discomfort, but the newly developed capsule (taken orally) can more easily obtain minute specimens of gastric juice from both children and adults. These capsules are a promising innovation for research science since EGF level might be an important variable in evaluating health status. The study described herein indicates that the capsules will be useful for future investigations into various benign and malignant diseases of the gastrointestinal tract.

Footnotes

Original title: China National Journal of New Gastroenterology (1995-1997) renamed World Journal of Gastroenterology (1998-).

L- Editor: Filipodia E- Editor: Liu WX

References
1.  Savage CR, Cohen S. Epidermal growth factor and a new derivative. Rapid isolation procedures and biological and chemical characterization. J Biol Chem. 1972;247:7609-7611.  [PubMed]  [DOI]
2.  Lu GJ, Hou X, Cheng YF, Huan BR, Chai LW. Radioimmunoassay of human epidermal growth factor (h-EGF) and characterization of domestically produced antiserum against h-EGF by genetic engineering. Zhonghua Heyixue Zazhi. 1993;13:22-24.  [PubMed]  [DOI]
3.  Konturek SJ. Role of growth factors in gastroduodenal protection and healing of peptic ulcers. Gastroenterol Clin North Am. 1990;19:41-65.  [PubMed]  [DOI]