How much oxygen does a mouse consume? - briefly
A typical 25‑gram adult mouse uses roughly 150–200 mL of O₂ per kilogram per hour, equating to about 3–5 mL of oxygen each hour. This rate reflects the animal’s basal metabolic demand under standard laboratory conditions.
How much oxygen does a mouse consume? - in detail
Oxygen utilization by a laboratory mouse depends on body mass, physiological state, ambient temperature, and activity level. A typical adult mouse weighing 20–30 g exhibits a basal oxygen uptake of approximately 0.12–0.16 ml O₂ · g⁻¹ · min⁻¹. Expressed per animal, this translates to 2.4–4.8 ml O₂ · min⁻¹, or 144–288 ml O₂ · h⁻¹. When expressed per kilogram of body weight, the resting value ranges from 6.0 to 7.5 L O₂ · kg⁻¹ · h⁻¹.
During moderate exercise (e.g., treadmill running at 10 m · min⁻¹) oxygen consumption can increase three‑ to four‑fold, reaching 0.4–0.6 ml O₂ · g⁻¹ · min⁻¹ (8–12 ml O₂ · min⁻¹ for a 20‑g mouse). Maximal aerobic capacity (VO₂max) reported for mice of the C57BL/6 strain approaches 0.9–1.2 ml O₂ · g⁻¹ · min⁻¹, equivalent to 18–24 ml O₂ · min⁻¹ for a 20‑g individual.
Temperature exerts a strong influence. At a thermoneutral zone of ~30 °C, basal consumption falls to the lower end of the range (≈0.10 ml O₂ · g⁻¹ · min⁻¹). Below thermoneutrality, metabolic heat production rises; at 22 °C, values increase by 20–30 %.
Sex and age modify rates modestly. Adult males typically show 5–10 % higher oxygen uptake than females of the same strain. Young mice (4–6 weeks) display elevated metabolic rates (≈0.18 ml O₂ · g⁻¹ · min⁻¹) relative to mature adults, reflecting rapid growth.
Measurement is performed with indirect calorimetry. In an open‑flow system, inspired and expired gas concentrations are recorded, and oxygen consumption (VO₂) is calculated as:
VO₂ = (F_i · V̇_i) – (F_e · V̇_e),
where F_i and F_e are fractional O₂ concentrations of inflow and outflow, and V̇_i and V̇_e are volumetric flow rates. Closed‑chamber methods integrate the decline in O₂ over a known volume and time. Results are reported in milliliters per minute, per gram, or per kilogram per hour.
Conversion to energy expenditure uses the respiratory quotient. Assuming an average RQ of 0.85, 1 ml O₂ yields ≈4.86 kJ (≈1.16 kcal). Thus, a resting 25‑g mouse expends roughly 0.7–1.0 kcal · h⁻¹, while vigorous activity can raise expenditure to 3–5 kcal · h⁻¹.
In summary, a standard adult mouse consumes 2–5 ml O₂ per minute at rest, up to 10–12 ml O₂ per minute during moderate exercise, and can reach 18–24 ml O₂ per minute at maximal aerobic capacity. These values are modulated by ambient temperature, strain, sex, and developmental stage.