PORTAL BLOOD PRESSURE AND ITS INFLUENCE UPON DIURESIS IN UNANESTHETIZED RATS

1. In unanesthetized rats the portal blood pressure was varied and the diuresis simultaneously recorded. 2. A short lasting increase of pressure (about 20-30 sec) causes anuria during the time of elevation. Pressure elevations for a longer time lead to an additional antidiuresis for about 30-40 min. Under the condition of osmotic diuresis the anuric phase can be observed only. 3. Lowering of portal pressure is accompanied by an increase of urine flow under the conditions of water or osmotic diuresis as well. 4. The existence of stretch receptors in the portal circulation is discussed, whose activity can affect either renal blood flow or the release of ADH. © 1969 Springer-Verlag.