COBALT-INDUCED POLYCYTHEMIA

I. CLINICAL AND HEMATOLOGIC OBSERVATIONS

¹ Division of Oral Pathology, School of Dentistry, University of Minnesota, Minneapolis, Minn.

1. Polycythemia was produced in mice and rats after injection of a cobaltous salt for 4 to 5 weeks. Red blood cell counts leveled off by the eighth week and remained more or less constant.

2. Hemoglobin values were quite regular for the controls and very irregular for the experimental animals.

3. The mean corpuscular hemoglobin is less in the experimental animals than in the controls for 14 weeks.

4. Maximum hemoglobin values were reached about 2 weeks earlier than maximum red blood cell counts.

5. No difference was noted in the differential white blood cell counts between the control and experimental groups.

6. Cobaltous nitrate seems to slow the rate of growth in male rats but not in females.

7. The effective dose on a weight basis is different for rats and for mice. An intraperitoneal overdose of cobaltous nitrate in rats is manifest by a temporary paralysis of the hindquarters.

8. Histologic study of the organs and bones of adult male mice with 15 weeks of cobalt administration has shown no significant changes.