Fig. 2.

(A–D) Normoxic respiratory and metabolic parameters recorded in adult mice – male (M) and female (F), wild type (+/+) or KO (−/−) for the progesterone receptors. (A) Minute ventilation (ml/min/g^0.855), (B) tidal volume (ml/g^1.043), (C) O₂ consumption rate (ml/min/g1.044 ), (D) CO₂ production rate (ml/min/g1.103 ). (E and F) Hypoxic response for minute ventilation (10% O₂ – 30 min) in males (E) and females (F). *p < 0.05 −/− vs. +/+ mice. ^$ p < 0.05 males vs. females. Number of animals for each group: males: (+/+ n = 13; −/− n = 6), females (+/+ n = 13; −/− n = 19).