Tissue Pigment Manifestations of Adaptation to High Altitudes

Abstract
Studies on the pigment content of muscle and organ tissues of sea level and altitude (14,900 ft.) guinea pigs have demonstrated a significant increase in myoglobin in several skeletal muscles, heart and liver in sea level animals kept in the altitude for an average of 75 days. Smaller increments were indicated for the myoglobin and cytochrome c levels for the altitude compared to the sea level groups. Higher blood hemoglobin values and higher ratios of heart weight to body weight and red to white tissue in several muscles were observed for the altitude guinea pigs and add to the total body content of respiratory pigments. The relationship of pigment levels to enzyme activities and the utility of various methods for measuring tissue pigments are discussed.