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Unrestrained Barometric Plethysmography During Air and Hypoxic Exposures in Old Mice Fed a Capsaicin Rich or Control Diet
Author(s) -
Russell Jacob D,
Receno Candace N,
Cunningham Caitlin M,
Deruisseau Keith C,
Deruisseau Lara R
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.551.25
Subject(s) - capsaicin , tidal volume , ventilation (architecture) , respiratory system , plethysmograph , anesthesia , respiratory minute volume , respiratory rate , respiration , trpv1 , control of respiration , stimulation , medicine , room air distribution , chemistry , endocrinology , zoology , receptor , heart rate , transient receptor potential channel , biology , anatomy , mechanical engineering , physics , blood pressure , engineering , thermodynamics
Capsaicin is the primary active ingredient in chili peppers and is an agonist for transient receptor potential vanilloid 1 (TRPV1). TRPV1 receptors are found in mammalian respiratory airways and pleural afferents (Takemura, 2008). The stimulation of these receptors by capsaicin augments respiratory responses in anesthetized mice with low doses (Roy, 2012) and increases breathing frequency of anesthetized mice upon intracarotid injection (Wang, 2006). Because pulmonary functions tend to deteriorate with age, our study aimed to examine the effects of dietary capsaicin on the respiratory response of aged mice. We hypothesized old mice fed capsaicin would display maintained ventilation compared to mice fed a control diet. Unrestrained barometric plethysmography (UBP) was used to quantify breathing frequency (F, breaths/min), tidal volume (V T , mL/breath), minute ventilation (V E , mL/min), ratio of V T to inspiration time (V T /IT, mL/sec), and the ratio of V E to expired carbon dioxide (V E /V CO2 ) in mice breathing air (20.93% O 2 and .05% CO 2 ) and exposed to hypoxic conditions (10 % O 2 , 0 % oxygen) for 15 minutes. C57BL/6J male mice were tested at 22 months of age prior to any dietary intervention and again at 23 months of age after one month of a lecithin control diet (CON; 50mg/kg per food weight; n=12) or a capsaicin rich diet (CAP; 50mg/kg per food weight; n=10). Data are presented as % change from pre‐values at 22 months of age; mean±SD. There were no differences between groups (p>0.05) with air exposure for F (CON: −3.7 ± 26.9% vs CAP: 19.5 ± 51.7% breaths/min), V T ( CON: 13.8 ± 40.9% vs. CAP: −3.7% ± 22.4% mL/breath), V E (CON: 3.1 ± 35.6% vs. CAP: 16.0 ± 53.2% mL/min), V T /IT (CON: 55.6 ± 89.6%vs. CAP: 37.8 ± 109.1% mL/sec), or V E /V CO2 (CON: −13.7 ± 45.4% vs. CAP: 11.0 ± 72.1%). Hypoxic exposure revealed no differences (p>0.05) between groups for F (CON: −1.0 ± 23.0% vs. CAP: 6.3 ± 24.9% BPM), V T (CON: 29.0 ± 60.5% vs. CAP: 28.1 ± 49.8% mL/breath), V E (CON: 13.4 ± 33.2% vs. CAP: 17.8 ± 36.6% mL/min), V T /IT (CON: 11.4 ± 29.6% vs. CAP: 12.7 ± 48.3% mL/sec), or V E /V CO2 (CON: −15.1 ± 38.6% vs. CAP: 10.5 ± 65.6%). Therefore, our hypothesis was not supported as there were no differences between CON and CAP respiratory responses. We conclude that 50mg/kg of capsaicin in the diet does not alter ventilation in old mice. Support or Funding Information JDR supported by the McDevitt Undergraduate Research Fellowship in Natural Science and CNR supported by 1 R15 HD076379‐01A1S1 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .