HEMODYNAMICS IN BONE MARROW OF ANEMIC RABBITS WITH INCREASED HEMATOPOIESIS

In fifteen rabbits heniatopoiesis was stimulated by a grave phenylhydrazine anemia. When the hematopoietic activity was maximal as judged from the reticulocyte counts, 6 or 7 days after the first injection of phenylhydrazine, the left femur was perfused in situ through the nutrient artery by blood led through an extracorporal perfusion arrangement from the left carotid artery of the anesthetized animal. The blood flow, the nutrient artery perfusion pressure and the intramedullary venous pressure were recorded. The bone marrow blood flow was greater and varied less than in non‐anemic animals. The arterial vessels exhibited a weak ability to auto‐regulate flow and acetylcholine caused arterial dilatation showing that neither the grave anemia nor the great hematopoietic activity had brought about a maximal dilatation of the arterial vessels. The venous resistance to bone marrow blood flow was constantly small whereas it has previously been shown to vary greatly in non‐anemic animals. © 1969 Scandinavian Physiological Society