A transient role of the kidney in the maintenance of hypertension. 
Using the Prague hypertensive rat (PHR), a model derived from the Wistar rat, in which a normotensive parallel, the Prague normotensive rat (PNR), was bred from the same parent pair (so that transplantation of organs between both these parallel rat model lines results in no distinct signs of rejection), we were able to show that hypertension travels with the kidney.  Transplantation of a kidney from PHR to a bilaterally nephrectomized (BNX) PNR led to an increase in systolic blood pressure (SBP) in the recipient for 10 weeks after grafting.  Similarly, a decrease in SBP was seen in BNX PHR for the same period of time after grafting a kidney from PNR.  If, however, the SBP was measured over a longer period of time, because the elevated SBP slowly drops after grafting a kidney from PHR to BNX PNR, it is less than 130 mm Hg in the fourth month and thereafter.  If BNX PHR receives a kidney from PNR, the decrease in SBP is permanent, amounting to 126.3 +/- 12.7 mm Hg one year after transplantation.  The grafting of a heart from PHR to the abdominal aorta of PNR does not influence SBP.  In conclusion, the presence of a kidney from PHR is necessary for the development, but is not sufficient for the maintenance of hypertension.  The heart of PHR is not "hypertensogenic" as is the kidney.