Human embryonic kidneys in organ culture: abnormalities of development induced by decreased potassium

Human embryonic kidneys of 5 to 12 weeks of gestation were grown in organ culture. Potassium concentrations of 3 to 6 milliequivalents per liter produced decreased ureteral bud branching, failure of nephron induction, and occasional cystic dilatations of the ureteral bud. Normal development of the kidney occurred at potassium concentrations of 6.5 to 10 milliequivalents per liter. These studies confirm the importance of relative stability of the potassiunm concentration in the development of the embryonic kidney.