Effects of cold exposure on urinary catecholamines in Arctic lemmings

Abstract 1. 1. The time course and per cent increase in urinary norepinephrine excretion in Arctic lemmings with cold exposure resembles temperate mammals. 2. 2. The pattern of epinephrine excretion with cold exposure was different for both lemming species and different from other mammals. The brown lemming maintained an elevated level of excretion in the cold, but the varying lemming showed only a transient peak on day 1. 3. 3. The urinary catecholamine excretion levels in lemmings are much higher than values reported for other small mammals. This may be associated with the behavioral hyperactivity of the lemmings.