Epsilon cell Epsilon cell Epsilon cells (ε-cells) are endocrine cells found in the Islets of Langerhans and produce the hormone ghrelin. They were discovered in mice. In human fetal pancreases, single epsilon cells scattered in primitive exocrine tissue were observed to start aggregating into clusters after gestational week 13. From gestational week 21, epsilon cells were observed around developing islets, forming an almost continuous layer at the rim of the islets. In adult pancreas samples, they remained localized on the mantle of the islets in different amounts. Production of ghrelin with insulin, glucagon, or somatostatin was not detected during development. Co-production with
Effect of spaceflight on the human body responses of the human body in space. At the moment only rigorously tested humans have experienced the conditions of space. If off-world colonization someday begins, many types of people will be exposed to these dangers, and the effects on the very young are completely unknown. On October 29, 1998, John Glenn, one of the original Mercury 7, returned to space at the age of 77. His space flight, which lasted 9 days, provided NASA with important information about the effects of space flight in older people. Factors such as nutritional requirements and physical environments which have so far not been