1. Spontaneously hypertensive and normotensive rats were selectively bred from a single Wistar strain.
2. Cross-transplantation of kidneys from hypertensive to normotensive rats and vice versa was performed, the sole remaining kidney of the recipient later being excised. Kidneys were also transplanted from normotensive donors into normotensive recipients and from hypertensive to hypertensive.
3. Normotensive rats receiving a kidney from either a hypertensive or normotensive donor showed unchanged blood pressure on normal salt diet. High-salt diet produced a greater rise in recipients of hypertensive than in recipients of normotensive kidneys.
4. Normotensive kidneys reduced the blood pressure of hypertensive recipients, but transplanted hypertensive kidneys had no such effect.