A review on gastric leptin: the exocrine secretion of a gastric hormone

• 발행기관: 대한해부학회
• 저자명: Philippe Cammisotto Moise Bendayan
• 간행물 정보: 『Anatomy and Cell Biology』Vol.45(1), 1~16쪽, 전체 16쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2012.03.31

영문 초록

A major advance in the understanding of the regulation of food intake has been the discovery of the adipokine leptin a hormone secreted by the adipose tissue. After crossing the blood-brain barrier, leptin reaches its main site of action at the level of the hypothalamic cells where it plays fundamental roles in the control of appetite and in the regulation of energy expenditure. At first considered as a hormone specific to the white adipose tissue, it was rapidly found to be expressed by other tissues. Among these, the gastric mucosa has been demonstrated to secrete large amounts of leptin. Secretion of leptin by the gastric chief cells was found to be an exocrine secretion. Leptin is secreted towards the gastric lumen into the gastric juice. We found that while secretion of leptin by the white adipose tissue is constitutive, secretion by the gastric cells is a regulated one responding very rapidly to secretory stimuli such as food intake. Exocrine-secreted leptin survives the hydrolytic conditions of the gastric juice by forming a complex with its soluble receptor. This soluble receptor is synthesized by the gastric cells and the leptin-leptin receptor complex gets formed at the level of the gastric chief cell secretory granules before being released into the gastric lumen. The leptin-leptin receptor upon resisting the hydrolytic conditions of the gastric juice is channelled, to the duodenum. Transmembrane leptin receptors expressed at the luminal membrane of the duodenal enterocytes interact with the luminal leptin. Leptin is actively transcytosed by the duodenal enterocytes. From the apical membrane it is transferred to the Golgi apparatus where it binds again its soluble receptor. The newly formed leptin-leptin receptor complex is then secreted baso-laterally into the intestinal mucosa to reach the blood capillaries and circulation thus reaching the hypothalamus where its action regulates food intake. Exocrine-secreted gastric leptin participates in the short term regulation of food intake independently from that secreted by the adipose tissue. Adipose tissue leptin on the other hand, regulates in the long term energy storage. Both tissues work in tandem to ensure management of food intake and energy expenditure.

목차

Abstract

Introduction

Adipose Tissue

Gastric Mucosa

Gastric Versus Adipose Tissue Leptons

Gastric Leptin in the Intestinal Tract

Transcytosis of Gastric Leptin across the Intestinal Enterocytes

Conclusion

Acknowledgements

References

키워드

Leptin Adipose tissue Gastric mucosa Intestinal mucosa Regulation of appetite