Age-related changes in thermoregulation in male albino rats

摘要: Male Sprague Dawley rats were followed longitudinally from 3 to 24 months of age. Resting oxygen consumption (VO2), measured in the thermal neutral zone (29 ± 1.0°C) decreased 47% between and age with a stable period 6 9 months. Changes rectal temperature general changes VO2. On average decline was 0.8°C. Thermal conductance dropped initially remained during further periods. circulation index rose slightly 13 months, thereafter When animals exposed mild cold challenge (18–19°C for 90 min.), increase VO2 same At this significantly higher. The capacity non-shivering thermogenesis (NST) after norepinephrine stimulation declined NST at These results suggest that shivering (ST) may be main source heat production old organism when faced challenge. Since ST is more consuming than it explain accidental hypothermia which occurs often elderly.