Sustained shivering is necessary for development of cold-induced hypertension in rats

To test the hypothesis that sustained shivering is a determining factor in development of hypertension in rats subjected to prolonged exposure to cold, the effect of cold exposure to 6 degrees C was examined in two experimental models with reduced shivering response to cold: aged (18 months old) rats and adult rats (8 months old) preacclimated to a less severe cold. The slow increase of colonic temperature in response to 6 degrees C cold, characteristic for reduced shivering, was observed in both experimental groups, while systolic pressure failed to increase. Results support the hypothesis that sustained shivering is a determining factor in development of cold-induced hypertension. Published by Elsevier Science Ltd.