During the study of an inbred strain of Wistar rats which spontaneously develop hypertension when they reach a weight of approximately 150 g, it was found that these animals also develop an erythrocytosis. A significant increase in red cell count was observed in spontaneously hypertensive (SH) rats (8-11 × 106 RBC/mm3) when compared with normotensive rats (6-7 × 106 RBC/mm3) of the same strain. This increase in red cell count paralleled the increase in body weight and the rise in blood pressure.
Subha Sen, George C. Hoffman, Nicholas T. Stowe, Robert R. Smeby, F. Merlin Bumpus