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
Apocrine sweat gland ducts. The tubules are wrapped in myoepithelial cells, which are more developed than in their eccrine gland counterparts. In hoofed animals and marsupials, apocrine glands act as the main thermoregulator, secreting watery sweat. For most mammals, however, apocrine sweat glands secrete an oily (and eventually smelly) compound that acts as a pheromone, territorial marker, and warning signal. Being sensitive to adrenaline, apocrine sweat glands are involved in emotional sweating in humans (induced by anxiety, stress, fear, sexual stimulation, and pain). In a five-month-old human fetus, apocrine glands are distributed all over the body; after a few weeks, they exist in