Four weeks of repetitive acute hypoxic preconditioning did not alleviate allergen-induced airway dysfunction in rats

• Published in: Respiratory physiology & neurobiology 2023-01, Vol.307, p.103982-103982, Article 103982
• Main Authors: Song, Ruolin, Broytman, Oleg, Liang, Nicole, Setzke, Jonathan, Setzke, Christopher, Wojdyla, Gabriela, Pegelow, David F., Osman, Fauzia, Sorkness, Ronald L., Watters, Jyoti J., Teodorescu, Mihaela
• Format: Article
• Language: English
• Subjects: Allergens; Allergic airway inflammation; Animals; Blood pressure; Hypoxia; Intermittent hypoxia; Lower airway; Lung; Methacholine Chloride - pharmacology; Pyroglyphidae; Rats
• ISSN: 1569-9048; 1878-1519
• DOI: 10.1016/j.resp.2022.103982

Clinical case series suggest beneficial effects of low-dose intermittent hypoxia in asthma. We tested cardiopulmonary effects of repetitive acute hypoxic preconditioning (RAHP) during allergic inflammation. Brown Norway rats were sensitized to house dust mites (HDM) and exposed to 4-week RAHP or normoxia (SHAM), concurrent with weekly HDM or saline (SAL) challenges. We assessed methacholine responses and lung HIF-1α expression at endpoint, and weekly blood pressure (BP). RAHP relative to SHAM: 1) in HDM-challenged rats, showed no protection against HDM-induced airway dysfunction and did not significantly impact BP (week 4 mean BP difference = 10.51 mmHg, p = 0.09) or HIF-1α expression; 2) in SAL-challenged rats, attenuated airway responses to methacholine, reduced BP (week 4 mean BP average difference = −8.72 mmHg, p = 0.04) and amplified HIF-1α expression (p = 0.0086). Four weeks of RAHP did not mitigate the allergen-induced lower airway dysfunction and may detrimentally affect BP. However, it elicited beneficial cardiopulmonary responses in SAL-challenged rats, concurrent with increased HIF-1α expression. •Four weeks of hypoxic preconditioning during allergic inflammation in rats:•did not prevent allergen-induced lower airway dysfunction.•did not significantly change systemic blood pressures.•elicited beneficial cardiopulmonary effects in the control animals.