Lung lipid composition in zinc-deficient rats

Area of Science:

• Biochemistry
• Nutritional Science
• Pulmonary Medicine

Background:

• Limited research exists on trace element effects on lung surfactant lipids.
• Zinc deficiency is a widespread nutritional issue with potential health implications.
• The role of zinc deficiency in adult respiratory distress syndrome (ARDS) requires investigation.

Purpose of the Study:

• To investigate the impact of moderate zinc deficiency on rat lung lipid metabolism.
• To explore the potential link between zinc deficiency and adult respiratory distress syndrome (ARDS).

Main Methods:

• Adult male Wistar rats were fed either a zinc-deficient (3 mg Zn/kg) or zinc-adequate (30 mg Zn/kg) diet for 2 months.
• Analysis included total lipids, phospholipids, cholesterol, triglycerides, protein concentration, and [Me-14C]choline incorporation into phospholipids (PC).
• Enzyme activity of CTP/phosphocholine cytidylyltransferase in lung microsomes was measured.

Main Results:

• Zinc deficiency led to increased total lipids, phospholipids, and cholesterol, with decreased triglycerides in the whole lung.
• Phospholipid (PC) concentration changed in specific lung compartments: increased in lamellar bodies and alveolar macrophages, decreased in extracellular surfactant.
• Protein concentration decreased, while [Me-14C]choline incorporation into PC and microsomal CTP/phosphocholine cytidylyltransferase activity increased in zinc-deficient rats.

Conclusions:

• Zinc deficiency significantly modifies lung lipid concentration, particularly phospholipids, suggesting an adaptive response.
• Altered phospholipid metabolism in zinc deficiency may play a role in lung function and potentially ARDS.
• Findings underscore the importance of zinc supplementation for high-risk groups and conditions like ARDS.