. 2021 Feb 4;130(4):1122–1132. doi: 10.1152/japplphysiol.00817.2020

Table 2.

Respiratory and metabolic responses before and after HH in WT and Olfr78^−/− mice

	Wild-Type Mice (n = 7)		Olfactory Receptor 78-Null Mice (n = 7)
	21% O₂	12% O₂	21% O₂	12% O₂
Pre-HH
RR, breaths/min	176 ± 4	221 ± 3^a	171 ± 3	204 ± 3^a^,c
V̇t, µL/g body wt	2.13 ± 0.09	2.60 ± 0.08^a	2.15 ± 0.07	2.49 ± 0.07^a
V̇e, mL/g body wt/min	0.38 ± 0.02	0.57 ± 0.02^a	0.37 ± 0.01	0.51 ± 0.02^a^,b
V̇o₂, mL/g body wt/min	0.053 ± 0.001	0.029 ± 0.001^a	0.051 ± 0.002	0.029 ± 0.001^a
V̇co₂, mL/g body wt/min	0.038 ± 0.001	0.027 ± 0.002^a	0.037 ± 0.001	0.026 ± 0.002^a
V̇e/V̇o₂	7.1 ± 0.4	20.7 ± 0.8^a	7.3 ± 0.4	16.9 ± 0.7^a^,b
Post-HH
RR, breaths/min	213 ± 4^e	260 ± 5^a^,e	184 ± 2^c,d	225 ± 4^a^,c,e
V̇t, µL/g body wt	2.59 ± 0.08^e	3.24 ± 0.09^a^,e	2.48 ± 0.07^d	2.90 ± 0.09^a^,b,e
V̇e, mL/g body wt/min	0.55 ± 0.03^e	0.84 ± 0.03^a^,e	0.46 ± 0.01^c,e	0.65 ± 0.02^a^,c,e
V̇o₂, mL/g body wt/min	0.057 ± 0.001^d	0.031 ± 0.001^a	0.058 ± 0.002^d	0.031 ± 0.002^a
V̇co₂, mL/g body wt/min	0.039 ± 0.001	0.027 ± 0.002^a	0.037 ± 0.002	0.027 ± 0.001^a
V̇e/V̇o₂	9.8 ± 0.3	27.5 ± 1.5^a^,e	8.0 ± 0.4	21.5 ± 1.2^a^,c,e

Values are means ± SE; n, number of mice of each genotype. HH, hypobaric hypoxia; Pre-HH, prehypobaric hypoxia; post-HH, posthypobaric hypoxia; Olfr78^−/− mice, olfactory receptor 78 null mice; RR, respiratory rate; V̇t, tidal volume; V̇e, minute ventilation; V̇o₂, oxygen consumption; V̇co₂, CO₂ production; V̇e/V̇o₂, ratio of minute ventilation/oxygen consumption; WT, wild-type. Statistical analysis was analyzed by two-way ANOVA with repeated measures followed by a Tukey’s test.

^{^a}

P < 0.01 compared with values with breathing at 21% O₂; ^bP < 0.05 and ^cP < 0.01 compared with wild-type mice; ^dP < 0.05 and ^eP < 0.01 compared with pre-HH.