- Reduction of sympathetic hyperactivity by enalapril in patients with chronic renal failure. Ligtenberg, G., Blankestijn, P.J., Oey, P.L., Klein, I.H., Dijkhorst-Oei, L.T., Boomsma, F., Wieneke, G.H., van Huffelen, A.C., Koomans, H.A. N. Engl. J. Med. (1999)