Thyroid Function Modulates Lung Fluid and Alveolar Viscoelasticity in Mechanically Ventilated Rat

Area of Science:

• Pulmonary Medicine
• Endocrinology
• Critical Care

Background:

• Mechanical ventilation (MV) is vital but can cause lung injury.
• Thyroid hormones (THs) aid alveolar fluid clearance and mitigate hypoxia-induced lung injury.
• Ventilator-induced lung injury (VILI) mechanisms differ from hypoxia-induced injury.

Purpose of the Study:

• To investigate the influence of thyroid function on lung extravascular fluid (LF), aquaporin 5 (AQP 5) expression, and alveolar viscoelasticity (AVE) in rats undergoing MV.
• To determine if thyroidal status modulates VILI.

Main Methods:

• Hypothyroid and hyperthyroid rat models were established.
• High-tidal volume MV was used to induce lung injury.
• LF, AQP 5 expression, and AVE were assessed using established physiological and biochemical techniques.

Main Results:

• Injurious MV altered LF and AVE, with effects dependent on thyroid function.
• Hyperthyroidism reduced LF and increased AQP 5 expression, improving AVE.
• Hypothyroidism showed contrasting effects on LF, AQP 5 expression, and AVE compared to hyperthyroidism.

Conclusions:

• Thyroid function significantly influences LF, AQP 5 expression, and AVE in mechanically ventilated lungs.
• The impact of thyroid status on VILI is substantial.
• Consideration of thyroid function is recommended for patients undergoing MV.