Myocardial capillaries in rats with cobalt-induced polycythemia

¹ Department of Medicine, Cornell University Medical College, New York City

Studies have been carried out on normal male and female rats of the Carworth-Nelson strain to ascertain myocardial capillary change after cobalt-induced polycythemia. There was a significant increase in blood hemoglobin and hematocrit, but there was no significant increase in the number of myocardial capillaries. There was a statistically significant increase in the ratio of capillary to tissue area. These results secondary to polycythemia were interpreted as suggesting engorgement of capillaries or dilatation of capillaries not readily visible in control animals.