The kidney as a determinant of genetic hypertension: evidence from renal transplantation studies.

Several lines of evidence suggest that the kidney plays an important role in the genesis of primary hypertension in humans and genetic hypertension in animals. Perhaps the most compelling evidence derives from clinical1–4 and experimental renal transplantation studies,5–36 which have been performed over the last 3 decades. In virtually all of these studies, the genetic background of the donor kidney had a major impact on long-term blood pressure in the recipients. More specifically, renal grafts from genetically hypertensive donors increased blood pressure in genetically normotensive recipients, whereas renal grafts from genetically normotensive donors lowered blood pressure in genetically hypertensive recipients. In many but not all of the studies, blood pressure traveled with the kidney in both directions. Although these data clearly show that the kidney is an important determinant of long-term blood pressure in normotension and primary or genetic hypertension, several major problems still remain unresolved. These problems relate mainly to the interpretation of the data and to the potential mechanisms by which the kidney sets the level of long-term blood pressure. In this brief review, we discuss the results and implications of clinical and experimental renal transplantation studies in primary hypertension in humans and genetic hypertension in animals that have been published to date.