The significance of body sodium content in hypertension following renal transplantation: exchangeable sodium and plasma renin concentration before and after renal transplantation.

The purpose of the present study was to determine the importance of body sodium content in hypertension following renal transplantation using measurements of exchangeablesodium (NaE) before and after transplantation. Plasma renin concentration (PRC) was also investigated. In the present study the necessity of a reference for expressing NaE values was eliminated because the subjects investigated acted as their own controls. The study included fourteen recipients, of whom seven were normotensive with an average blood pressure (BP) of 136/84 mmHg and seven were hypertensive with an average BP of 182/113 mmHg after renal transplantation. In the hypertensive NaE increased significantly (mean 22%) in contrast to an insignificant decrease in NaE in the normotensives (mean, -5%). The change in NaE was positively correlated to the mean BP after renal transplantation (p = 0.69, n = 14, P less than 0.02). BP and NaE were not correlated to prednisone dosages. PRC was normal in all the hypertensives. The results strongly suggest that sodium accumulation in the body, which is not prednisone-dependent, is involved in the pathogenesis in post-transplant hypertension.