Oxygenation through oral Ox66 in a two-hit rodent model of respiratory distress

Figures & data

Figure 1. Interstitial oxygen tension (P_ISFO₂) of skeletal muscle capillary beds. The microvasculature of the spinotrapezius muscle was monitored at specific sites for interstitial fluid oxygenation throughout the experimental time course. Two-Way ANOVA detected no differences up to 60 min but saw post-treatment separation between NS and oxygen-containing treatments. About 40% FiO₂ was higher than Ox66 for time points 60 and 75 (not illustrated). Data are mean SEM. Statistical annotation colour-coded to indicate significance vs. NS. *p < 0.05 vs. NS.

Table 1. Arterial blood gasses and metabolites.

Minutes	0	60	120	180	240
	pH
NS	7.34 + 0.01	7.15 + 0.03^BL	7.13 ± 0.03^BL	7.11 ± 0.04^BL	7.11 ± 0.03^BL
Ox66	7.35 ± 0.01	7.15 ± 0.02^BL	7.14 ± 0.02^BL	7.15 ± 0.03^BL	7.13 ± 0.03^BL
40% FiO2	7.35 ± 0.01	7.17 ± 0.03^BL	7.20 ± 0.02^BL	7.19 ± 0.02^BL	7.17 ± 0.02^BL
	PCO2 (mmHg)
NS	34 ± 1	60 ± 3^BL	64 ± 3^BL	61 ± 4^BL	63 ± 4^BL
Ox66	37 ± 1	59 ± 3^BL	62 ± 3	56 ± 2^BL	56 ± 3^BL
40% FiO2	35 ± 2	62 ± 4^BL	58 ± 4^BL	57 ± 2^BL	60 ± 2^BL
	PAO2 (mmHg)
NS	91 ± 3	64 ± 4^BL	58 ± 3^BL	56 ± 4^BL	54 ± 4^BL
Ox66	92 ± 3	60 ± 4^BL	60 ± 4^BL	60 ± 4^BL	60 ± 4^BL
40% FiO2	90 ± 1	61 ± 5^BL	124 ± 5^BL*^α	128 ± 7^BL*^α	122 ± 4^BL*^α
	SO2 (%Oxyhemoglobin)
NS	90 ± 1	63 ± 5^BL	59 ± 4^BL	56 ± 5^BL	52 ± 8^BL
Ox66	90 ± 2	59 ± 5^BL	59 ± 4^BL	62 ± 5^BL	62 ± 4^BL
40% FiO2	91 ± 0.4	61 ± 6^BL	95 ± 1^BL*^α	94 ± 1^*α	94 ± 1^*α
	Glucose (mg/dL)
NS	113 ± 6	188 ± 16^BL	156 ± 17	118 ± 12	97 ± 23
Ox66	108 ± 4	144 ± 19	185 ± 37	157 ± 17	119 ± 26
40% FiO2	100 ± 5	169 ± 22	126 ± 9	113 ± 5	119 ± 10
	Lactate (mg/dL)®
NS	12 ± 1.1	12 ± 2.3	17 ± 4.4	28 ± 9.6	31 ± 8.4
Ox66	8.5 ± 0.9	8.9 ± 2.4	15.0 ± 3.1	19.8 ± 3.3^BL	27.9 ± 10.6
40% FiO2	9.8 ± 1.1	12 ± 3.4	5 ± 1.0^BL^α	7 ± 0.6^α	7 ± 1.0

Small volume (65 μL) blood draws were analysed every hour to minimize sampling impact on injury severity. Metrics evaluated provide indicators of acidosis (pH), gas exchange efficiency (pCO₂ and pO₂) and unmet oxygen demand (lactate). N = 8 per group. Data are mean ± SEM.

^BL p < 0.05 vs. 0 min (BL).

* p < 0.05 vs. NS.

^α p < 0.05 vs. Ox66.

Figure 2. The P_AO₂/FiO₂ index of pulmonary function. Arterial blood samples were used to measure P_AO₂, which was then divided by the fraction of inspired oxygen (FiO₂) – 21% for NS and Ox66. 40% FiO₂ returned the index to BL, while NS and Ox66™ had similar profiles. N = 8 per group. Data are mean ± SEM. ^βp < 0.05 vs. 0 min.

Figure 3. Mean arterial pressure. Arterial pressure data were collected continuously through an indwelling catheter and plotted at discrete time points to align with P_ISFO₂ collection. Measurements before treatment did not differ between groups. NS and Ox66™ were virtually identical and remained suppressed from their BL. About 40% FiO₂ was significantly elevated against most NS and Ox66 time points after treatment. It was also suppressed versus its BL but at a lower magnitude. Statistical annotations are colour-coded to correspond to their specific group. N = 8 per group. Data are mean ± SEM. *p < 0.05 vs. NS. ^αp < 0.05 vs. Ox66.

Table 2. Inflammatory biomarkers.