1. An Eosinophil Hypothesis for Functional Dyspepsia
Marc E. Rothenberg, MD, PhD, Mitchell B. Cohen, MD 
Clinical Gastroenterology and Hepatology 
Volume 5, Issue 10, Pages (October 2007)
DOI: /j.cgh
Copyright © 2007 AGA Institute Terms and Conditions

2. Figure 1
Schematic diagram of an eosinophil and its multifunctional effects. Eosinophils are resident cells in the intestinal lamina propria and increase in levels and clustering in select intestinal disorders. Eosinophils are bilobed granulocytes with eosinophilic staining secondary granules. The secondary granules contain 4 primary cationic proteins designated EPO, MBP, ECP, and EDN. All 4 proteins are cytotoxic molecules. In addition to releasing their preformed cytotoxic proteins, eosinophils can also release a variety of cytokines, chemokines, and lipid mediators. Eosinophils directly communicate with T cells and mast cells in a bidirectional manner. Eosinophils activate T cells by serving as antigen-presenting cells, and eosinophil-derived MBP is a mast cell secretagogue. Eosinophils can also regulate T-cell polarization through synthesis of indoleamine 2,3-dioxygenase (IDO), an enzyme involved in oxidative metabolism of tryptophan, catalyzing the conversion of tryptophan to kynurenines (KYN), a regulator of Th1/Th2 balance. Eosinophils can cause neurologic dysfunction by interfering with the function of muscarinic receptors as well as by the release of neuromediators including nerve growth factor (NGF), vasoactive intestinal peptide (VIP), and substance P. In addition, eosinophil-derived products such as leukotrienes (LT), platelet-activating factor (PAF), and interleukin-13 can induce smooth muscle activation and proliferation.
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions