kjpp The Korean Journal of Physiology & Pharmacology Korean J Physiol Pharmacol 1226-4512 2093-3827 Korean J Physiol Pharmacol 10.4196/kjpp.2011.15.3.137 kjpp-15-137 Original Article Influence of Exposure to Extremely Low Frequency Magnetic Field on Neuroendocrine Cells and Hormones in Stomach of Rats HongMin Eui 1 ∗ YoonKyu Hyun 3 ∗ JungYoon Yang 1 LeeTae Jin 1 ParkEon Sub 1 SohnUy Dong 4 JeongJi Hoon 2 Department of Pathology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul 156-756, Korea Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea Corresponding to: Ji Hoon Jeong, Department of Pharmacology, College of Medicine, Chung-Ang University, 221, Heuksuk-dong, Dongjak-gu, Seoul 156-756, Korea. (Tel) 82-2-820-5688, (Fax) 82-2-826-8752, (E-mail) jhjeong3@cau.ac.kr

The authors contribute equally to this paper and share the first authorship.

 022011 18022011 15 3 137 142 20042011 30052011 15062011 Copyright © 2011 Korean J Physiol Pharmacol 2011 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract

Extremely low frequency magnetic fields (ELF-MF) have the ability to produce a variety of behavioral and physiological changes in animals. The stomach, as the most sensitive part of the neuroendocrine organ of the gastrointestinal tract, is crucial for the initiation of a full stress response against all harmful stress. Thus, the purpose of this study was to examine whether ELF-MF stimuli induce changes in the activity of neuroendocrine cells, considering their involvement in endocrine or paracrine effect on surrounding cells. The exposure to ELF-MF (durations of 24 h and 1 or 2 weeks, 60 Hz frequency, 0.1 mT intensity) altered the distribution and occurrence of gastrin, ghrelin and somatostatin-positive endocrine cells in the stomach of rats. The change, however, in the secretion of those hormones into blood from endocrine cells did not appear significantly with ELF-MF exposure. Comparing with sham control, ELF-MF exposure for 1 and 2 week induced an increase in BaSO4 suspension propelling ratio of gastrointestinal tract, indicating that ELF-MF affects gastrointestinal motility. Our study revealed that ELF-MF exposure might influence the activity of endocrine cells, an important element of the intrinsic regulatory system in the digestive tract. The pathophysiological character of these changes and the mechanism responsible for neuroendocrine cell are still unclear and require further studies.

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Gastrin-positive cells mainly in the basal portion of the antral mucosa. (A) Sham control, (B) ELF-MF (durations of 24 h and 2 weeks, 60 Hz frequency, 0.1 mT intensity) exposure, ×200.

Ghrelin-positive cells mainly in the basal portion of the antral mucosa. (A) Sham control, (B) ELF-MF (durations of 24 h and 2 weeks, 60 Hz frequency, 0.1 mT intensity) exposure, ×200.

Somatostatin-positive cells mainly in the basal portion of the antral mucosa. (A) Sham control, (B) ELF-MF (durations of 24 h and 2 weeks, 60 Hz frequency, 0.1 mT intensity) exposure, ×200.

Changes in the number of gastrin-positive neuroendocrine cells in rat stomach. Data represent mean±SD, n=7. ∗p<.05 versus sham.

Changes in the number of ghrelin-positive neuroendocrine cells in rat stomach. Data represent mean±SD, n=7. ∗p<.05 versus sham.

Changes in the number of somatostatin-positive neuro-endocrine cells in rat stomach. Data represent mean±SD, n=7. ∗p<.05 versus sham.

Effect of ELF-MF on BaSO4 suspension propelling ratio of gastrointestinal tract. Comparing with sham control, ELF-MF induced an obvious increase in the propelling ratio. Data represent mean±SD, n=5∼8. ∗p<.05 versus sham.

Changes in the blood level (pg/ml) of gastrin, ghrelin and somatostatin

  Gastrin Ghrelin Somatostatin
Sham 141.2 (3.9) 130.7 (5.8) 81.8 (9.6)
ELF-MF (1 week) 146.1 (7.0) 127.6 (8.3) 89.9 (9.0)
ELF-MF (2 week) 144.4 (7.0) 127.6 (9.5) 88.1 (4.7)

Average (SD).