Premium
Water deprivation enhances the hypercapnic ventilatory response in rats
Author(s) -
Nakai Larissa Bonassi,
Silva Elaine Fernanda,
Menani José Vanderlei,
Colombari Débora Simões Almeida,
Zoccal Daniel Breseghello,
Colombari Eduardo
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.560.5
Subject(s) - hypercapnia , tidal volume , ventilation (architecture) , zoology , chemistry , anesthesia , endocrinology , control of respiration , respiratory rate , medicine , respiratory system , respiratory minute volume , plethysmograph , heart rate , blood pressure , biology , mechanical engineering , engineering
Behavioral, neuroendocrine, autonomic and cardiovascular adjustments are triggered during water deprivation. However, the effects of water deprivation on ventilation remain to be determined. Herein, we evaluated the pulmonary ventilation after 48 h of water deprivation in male Holtzman rats (280–300 g) under unanesthetized conditions. Control rats (n=7) had continuous access to tap water and food, whereas water‐deprived (WD, n=6) rats had water, but not food removed for 48 h before the experiments. Rats were placed in whole‐body plethysmographic chamber (5 L) to measure the respiratory frequency (fR), tidal volume (V T ) and minute ventilation (V E ) under baseline condition (room air) and during hypercapnia (7% CO 2 for 5 min). After the experiments, animals were decapitated for blood collection. WD rats had an increase in serum osmolality (307 ± 1 mOsmol/kg of water, vs . control: 297 ± 1 mOsmol/kg of water; p<0.05) and sodium concentration (148 ± 0.6 mmol/L, vs . control: 141 ± 0.5 mmol/L; p<0.05). WD rats exhibited increased V T (9.7 ± 0.5 mL.kg −1 , vs . control: 7.7 ± 0.3 mL.kg −1 ; p<0.05) but reduced fR (76 ± 2 breaths.min −1 , vs . control: 103 ± 7 breaths.min −1 ; p<0.05) compared to controls. As a result, baseline V E (746 ± 54 mL.kg −1 .min −1 , vs . control: 799 ± 64 mL.kg −1 .min −1 ) were similar between groups. Under hypercapnia, the response of increases in V T were statistically similar between WD and control groups (ΔV T : 60 ± 16%, vs . control: 33 ± 7%). On the other hand, WD rats demonstrated amplified hypercapnia‐induced increases in fR (Δ: 47 ± 5%, vs . control: 19 ± 5%; p<0.05) and V E (Δ: 140 ± 35%, vs . control: 59 ± 9%; p<0.05). The results show that 48 h of water deprivation enhanced the ventilatory responses induced by hypercapnia in unanesthetized rats. Support or Funding Information FAPESP; CNPq This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .