Volume regulation during dehydration of desert beetles.

摘要: In arid areas in East Africa, dietary water is available only during the rainy seasons. Since seasons are separated by dry seasons, which may last for many months and extreme cases more than a year, beetles lose 80% of their body water. The loss takes place mainly at expense extracellular fluid, i.e. as haemolymph volume drops to zero, cell moderately reduced. protection requires that solutes removed from haemolymph. either excreted or sequestered within an osmotically inactive state. predatory family Carabidae, where Na dominating solute, excreted, but it can easily be replaced diet. most herbivorous beetles, such Tenebrionidae, feed on low diet, have levels, usually, not always, deposited body. Free amino acids moved cells, some seem made polymerization peptides. As become rehydrated, peptides rapidly depolymerized released Another factor, important stabilisation volume, colloid osmotic contribution intracellular proteins, steep increase activity with increasing concentration.