• Nephreetomized dogs given sodium parenterally and protein by diet develop acute hypertensive cardiovascular disease.' Protection, against acute renoprival hypertension of this type has been demonstrated for (a) intact renal tissue as exemplified by ureterocaval anastomosis, (b) autoexplanation of whole kidney or renal medulla, and (c) a crude extract of renal medulla. Both medullorenal extrac...