Determination of Ghrelin Immunoreactivity in the Pancreas Tissue of Rats Supplied with Melatonin

Abstract

Aim: This study aimed to determine the histological effect of melatonin administration on the pancreas and the localization of ghrelin, secreted from the pancreas, using immunohistochemical techniques. Material and Method: The study utilized 30 male Sprague Dawley rats aged 10–12 weeks. Melatonin was dissolved in ethanol and injected intraperitoneally into the experimental group at 10 mg/ kg for 21 days, diluted with a physiological saline solution. After the experimental period, pancreatic tissues were collected from the rats. These tissue samples were fixed in 10% formalin for histological and immunohistochemical examinations and underwent routine histological procedures. The tissues were then treated with a ghrelin antibody (diluted to 1/50) to determine the immunohistochemical localization of ghrelin. Results: Upon examination of the general histological structure of the pancreatic tissue, no differences were observed between the groups. Ghrelin immunoreactivity was detected in the islets of Langerhans and the pars initialis epithelium of the pancreas in both the sham and control groups but not in the melatonin group. Conclusion: Melatonin administration did not induce any histological disorders in the pancreas. However, it was found to decrease the ghrelin levels secreted from the pancreas.

Keywords

• ghrelin
• immunohistochemistry
• melatonin
• pancreas

References

1. 1. Liebmann PM, Wölfler A, Felsner P, Hofer D, Schauenstein K. Melatonin and the immune system. İnt. Arch. Allergy. İmmunol. 1997;112:203–211.
2. 2. Reiter RJ, Tan D, Osuna C, Gitto E. Actions of melatonin in the reduction of oxidative stress. J. Biomed Sci. 2000;7:444–458.
3. 3. Konturek SJ, Konturek PC, Brzozowska I, Pawlik M, Sliwowski Z, Czesnikiewicz-Guzik M, et al. Localization and biological activities of melatonin in intact and diseased gastrointestinal tract (GIT). J Physiol Pharmacol. 2007;58:381–405.
4. 4. Bubenik GA. Localization, physiological significance and possible clinical implication of gastrointestinal melatonin. Biol Signals Recept. 2001;10:350–366.
5. 5. Ebelt H, Peschke D, Bromme HJ, Morke W, Blume R, Peschke E. Influence of melatonin on free radicalinduced changes in rat pancreatic beta-cells in vitro. J Pineal Res. 2000;28:65–72.
6. 6. Kojima M, Hosada H, Date Y. Ghrelin is a growth hormone releasing acylated peptide from stomach. Nature. 1999;402:656–660.
7. 7. Kukol A. Ghrelin Vitamins and Hormon, The Structure of Ghrelin. 2008;77–79.
8. 8. Kojima M, Kangawa K. Ghrelin: structure and function. Physiol. 2005;85:495–522.

9. 9. Ariyasu H, Takaya K, Tagami T, Ogawa Y, Hosoda K, Akamizu T, et al. Stomach is a major source of circulating ghrelin, and feding state determines plasma ghrelin-like immunoreactivity levels in humans. J Clin Endocrinol Metab. 2001;86:4753–4758.
10. 10. Fujimiya M, Asakawa A, Ataka K, Chen CY, Kato I, Inui A. Ghrelin, des-acyl ghrelin, and obestatin: regulatory roles on the gastrointestinal motility. Int J Pept. 2010;
11. 11. Hosoda H, Kojima M, Matsuo H, Kangawa K. Purification and characterization of rat desGln14-Ghrelin, a second endogenous ligand for the growth hormone secretagogue receptor. J Biol Chem. 2000;275:21995–2000.
12. 12. Sakata I, Nakamura K, Yamazaki M, Matsubara M, Hayashi Y, Kangawa K, et al. Ghrelin-producing cells exist as two types of cells, closed- and opened-type cells, in the rat gastrointestinal tract. Peptides. 2002;23:531–536.
13. 13. Cowley M, Smith R, Diano, Tschop M, Pronchuk N, Stasburger C, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37:649–661.
14. 14. Korbonits M, Bustin SA, Kojima M, Jordan S, Adams EF, Lowe DG, et al. The expression of the growth hormone secretagogue receptor ligand ghrelin in normal and abnormal human pituitary and other neuroendocrine tumors. J Clin Endocrinol Metab. 2001;86:881–887.
15. 15. Date Y, Kojima M, Hosoda H, Sawaguchi A, Mondal MS, Suganuma T, et al. Ghrelin, a novel growth hormone-releasing acylated peptide, is synthesized in a distinct endocrine cell type in the gastrointestinal tracts of rats and humans. Endocrinology. 2000;141:4255–4261.
16. 16. Volante M, Allia E, Gugliotta P, Funaro A, Broglio F, Deghenghi R, et al. Expression of ghrelin and of the GH secretagogue receptor by pancreatic islet cells and related endocrine tumors. J Clin Endocrinol Metab. 2002;87:1300–1308.
17. 17. Chanoine JP, Wong AC. Ghrelin gene expression is markedly higher in fetal pancreas compared with fetal stomach: effect of maternal fasting. Endocrinology. 2004;145:3813–3820.
18. 18. Adeghate E, Ponery AS. Ghrelin stimulates insulin secretion from the pancreas of normal and diabetic rats. Journal of neuroendocrinology. 2002;14(7):555–560.
19. 19. Lee HM, Wang G, Englander EW, Kojima M, Greeley GH. Ghrelin, a new gastrointestinal endocrine peptide that stimulates insulin secretion: enteric distribution, ontogeny, influence of endocrine, and dietary manipulations. Endocrinology. 2002;143(1):185–190.
20. 20. Broglio F, Arvat E, Benso A, Gottero C, Muccioli G, Papotti M, et al. Ghrelin, a natural GH secretagogue produced by the stomach, induces hyperglycemia and reduces insulin secretion in humans. The Journal of Clinical Endocrinology & Metabolism. 2000;86(10):5083–5083.
21. 21. Melchiorri D, Reiter RJ, Attia AM. Potent protective effect of melatonin on in vivo paraquat-induced oxidative damage in rats, Life Sci. 1994;56:83–89.
22. 22. Akçay GB. Stretozotosin İle Diyabet Oluşturulan Sıçanlarda Bağırsak Dokusunda Gelişen Oksidan Hasara Karşı Melatonin Tedavisinin Olası Koruyucu Etkilerinin İncelenmesi, Marmara Üni., Sağlık Bilimleri Enstitüsü, Farmakoloji Anabilim Dalı, İstanbul, 2017
23. 23. Yüzüak H. Melatoninin streptozotosin kaynaklı deneysel diyabet üzerine olası koruyucu etkisi. Klinik ve Deneysel Araştırmalar Dergisi. 2014;5(4):592–598.
24. 24. Jaworek J, Szklarczyk J, Jaworek AK, Nawrot-Porąbka K, LejaSzpak A, Bonior J, et al. Protective Effect of Melatonin on Acute Pancreatitis. International Journal of Inflammation. 2012;1–8.
25. 25. Ross H, Wojciech Pawlina. Histology A Text and Atlas, Histoloji. ISBN 978–0–7817–7200–6, 2011.
26. 26. Bianchini M, Fantazzinni TR, Vieira DSC, Teive AM, Costa A. Quantitative immunohistochemical analysis of duodenal ghrelin cells after sleeve gastrectomy in Wistar rats, Acta Cirurgica Brasileira. 2012;27(9):535 599.
27. 27. Akbalık ME. Keklik (Alectoris chukar) Bağırsağında Ghrelin, Leptin ve Obestatin Dağılımı. Dicle Üniv Vet Fak Derg. 2019;12(2):117–121.
28. 28. Grönberg, M, Tsolakis AV, Magnusson, L, Janson ET, Saras J. İnsan Dokularında Obestatin ve Ghrelin Dağılımı. Histokimya ve Sitokimya Dergisi. 2008;56(9);793–801.
29. 29. Zhang W, Zhang Z, Chen J, Tong D. Ghrelin is Expressed in the Pregnant Mammary Glands of Dairy Goats and Promotes the Cell Proliferation of Mammary Epithelial Cells. Gen Comp Endocrinol. 2018;260:115–124.
30. 30. Tanaka-Shintani M, Watanabe M. Distribution of ghrelinimmunoreactive cells in human gastric mucosa: comparison with that of parietal cells. J Gastroenterol. 2005;40:345–349.
31. 31. Wang J, Li P, Zhang XT. Distribution and developmental changes of ghrelin-immunopositive cells in the pancreas of African ostrich chicks (Struthio camelus) . Poultry science. 2017;96(9):3445–3451. PMID:28595319.
32. 32. Wei FM, Li YL, Ye Y, Zhang YJ, Jiang QY. Localization and development of ghrelin-immunopositive cells in periphery organs of broiler chickens. Acta Vet. Zootech. Sin. 2010;41:341346.
33. 33. Fang FG, Li MQ, Tao Y, Jiang SD, Li FB. Immunohistochemical localization of ghrelin in the liver and pancreas of adult Wanxi white goose. Chin. J. Anat. 2008;31:28–30.
34. 34. Suzuki H, Yamamoto T. Ghrelin-and growth hormone secretagogue receptor- immunoreactive cells in Xenopus pancreas. Regul. Pept. 2011;169:64–69.
35. 35. Raghay K, Gallego R, Scoazec JY, Garcia-Caballero T, Morel G. Different ghrelin localisation in adult human and rat endocrine pancreas. Cell Tissue Res. 2013;352:487–494.
36. 36. Sönmez S. Sıçanlarda Pinealektomi ve Melatonin Uygulamasının Serum Melatonin, Nesfatin-1 ve Ghrelin Düzeylerine Etkisi. Selçuk Üni. Sağlık Bilimleri Enstitüsü, Yüksek Lisans Tezi, Konya, 2017