Lung lipid composition in zinc‐deficient rats

Abstract

There have been a limited number of studies investigating surfactant lipid changes in lung with trace elements. The present investigation was designed to examine the effect of moderate zinc deficiency on the lipid metabolism in rat lung. We also evaluated whether zinc deficiency, which is a wide-spread problem, could play a role in adult respiratory distress syndrome (ARDS). For that purpose, adult male Wistar rats were fed two diets differing in zinc concentration. The rats were divided into two groups. One group was fed a zinc-deficient diet containing 3 mg Zn/kg, and the other group received a zinc-adequate control diet with 30 mg Zn/kg according to AIN 93-M. After 2 mon of treatment, we observed that in the zinc-deficient group (i) total lipids, phospholipids, and cholesterol increased whereas TG decreased in whole lung; (ii) phospholipid (PC) concentration increased in lamellar bodies and alveolar macrophages and decreased in extracellular surfactant but did not change in microsomes; (iii) protein concentration decreased in whole lung, extracellular surfactant, lamellar bodies, and macrophages; (iv) the incorporation of [Me-14C]choline into PC (phospholipids) of lung slices increased; and (v) the activity of CTP/phosphocholine cytidylyltransferase bound to the microsomes increased in the lung. These results suggest that the lipid concentration in the lung (especially the phospholipids) is modified directly or indirectly by a zinc-deficient diet. In a zinc-deficient diet, the lung changes the pattern of PC for an adaptive or recovery stage. Therefore, zinc deficiency implications are important for the design of therapies and public health interventions involving targeted zinc supplementation for high-risk groups or groups with certain diseases, such as ARDS.

Serum zinc in critically ill adult patients with acute respiratory failure

“…Animal studies have demonstrated that zinc deficiency may affect lung and airway cells 3–7 and lead to more severe lung damage 5 . In a previous report of non‐critically ill elderly, normal compared with low serum zinc decreased the duration of pulmonary infections 9 .…”

“…Zinc may have a role in maintaining pulmonary epithelial cell integrity 3–5 . In addition, zinc deficiency in animal models changes lipid metabolism in lungs, 6 and may lead to pulmonary oedema by increasing pulmonary capillary permeability 7 . Anti‐inflammatory and anti‐oxidant effects of zinc may protect pulmonary epithelial cells during oxidative stress 8 …”

Alterations in the Lipid Metabolism of Rat Aorta: Effects of Vitamin A Deficiency

“…This coincided with a high expression of CT-α mRNA. The increased aorta cholesterol content could lead to an enhanced expression of CT-α mRNA [39, 40]. In addition, the increased fatty acid synthesis observed in the aorta of vitamin-A-deficient rats suggests a high availability of fatty acids to form PL.…”

Nutritional Deficiencies and Phospholipid Metabolism

“…The major phospholipid component (at the air-liquid interface) is phosphatidylcholine (70–80%) and numerous reports indicate that changes in phosphatidylcholine metabolism are a common feature of the pathophysiology of experimental chronic lung injury or adult respiratory distress syndrome. A moderate Zn deficiency ( in vivo ) can induce a physiological stimulus that enhances phospholipid synthesis and changes especially the pattern of phospholipids in adult rat lung [122,123]. …”