Effects of High Altitude and Cobalt on Growth and Polycythemia in Rats

Abstract

Rate of growth, as measured by wt. increase, is a function of altitude. Relative to control rats at 5300 ft. (Denver) the growth rate of animals was decreased during a 9-week residence at 14,150 ft. (Mt. Evans). Upon return to 5300 ft., the growth rate increased but never attained the final growth of control rats kept at this altitude. Higher altitudes caused a marked polycythemia and an increase in hemoglobin. Oral admn. of Co salts at the 14,150 ft. elevation caused a more marked decrease in growth than in control animals, also a more marked polycythemia and hemoglobin increase. Similar findings were obtained for control vs. Co-fed animals at 5300 ft. Growth was not affected at an intermediate altitude of 10,700 ft. (Echo Lake). Polycythemia and increase in hemoglobin did occur, however. Oral admn. of Co salts caused a decrease in growth and a more marked polycythemia and hemoglobin increase. Animals brought from the 10,700-ft. to the 5300-ft. elevation showed a decrease in red cells and hemoglobin. The values gradually approached those of the control animals at 5300 ft.