Nebulization of the acidified sodium nitrite formulation attenuates acute hypoxic pulmonary vasoconstriction

Respiratory Research

Table 1 The effect of nebulized nitrite and acidified forms of nitrite on the strength of HPV, Psa and CO in the in vivo model of catheterized rabbits.

		PB	PB + nitrite	PB + nitrite + citrate	p value
HPV	Baseline (mmHg)	1.24 ± 0.58	1.56 ± 0.38	1.79 ± 0.50	n.s.
	Nebulization (mmHg)	1.36 ± 0.50	0.52 ± 0.39	0.69 ± 0.72	p < 0.05
	(% of baseline value)	119.52 ± 36.74	32.28 ± 26.13	36.30 ± 51.32	p < 0.05
Systemic hypoxic hypotension	Baseline (mmHg)	-6.78 ± 1.97	-6.07 ± 0.64	-7.39 ± 2.61	n.s.
	Nebulization (mmHg)	-6.36 ± 1.27	-5.28 ± 1.39	-8.16 ± 0.85	n.s.
Cardiac output	Baseline (ml/min)	617.63 ± 15.96	725.64 ± 39.59	575.46 ± 34.64	n.s.
	Nebulization (ml/min)	556.79 ± 37.62	589.46 ± 33.28	533.05 ± 28.16	n.s.

HPV was calculated as the difference between the maximum Ppa during hypoxia and the Ppa during normoxia. For percentage calculations, the strength of HPV during the second hypoxic challenge was set to 100%, and the value of HPV during nebulization was related to it. Nitrite alone and in acidified forms nebulized during the third hypoxic maneuver significantly inhibited HPV. CO was measured by Fick's method. Blood samples for analysis were drawn during normoxia and at the end of the third hypoxic challenge. Psa was monitored continuously using a catheter placed in the left carotid artery. Values represent the difference between Psa during normoxia and Psa during subsequent hypoxia.

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