Fetal kidney in organ culture: abnormalities of development induced by decreased amounts of potassium.

Kidneys from fetal mice (10 to 18 days' gestation) were grown in organ culture. Concentrations of potassium less than 9 milliequivalents per liter (10- to 14-day kidneys), and less than 6 milliequivalents per liter (14- to 18-day kidneys), produced abnormal branching, failure of nephron induction, and occasional cystic dilatations of the ureteral bud. These studies emphasize the importance of an environment with a high concentration of potassium for development of the fetal kidney.