Mrnka L, Nováková O, Novák F, Tvrzická E, Pácha J
Institute of Physiology, Czech Academy of Sciences, Prague.
Physiol Res. 2000;49(2):197-205.
The effect of low-salt diet on phospholipid composition and remodeling was examined in rat colon which represents a mineralocorticoid target tissue. To elucidate this question, male Wistar rats were fed a low-salt diet and drank distilled water (LS, low-salt group) or saline instead of water (HS, high-salt group) for 12 days before the phospholipid concentration and fatty acid composition of isolated colonocytes were examined. The dietary regimens significantly influenced the plasma concentration of aldosterone which was high in LS group and almost zero in HS group. Plasma concentration of corticosterone was unchanged. When expressed in terms of cellular protein content, a significantly higher concentration of phospholipids was found in LS group, with the exception of sphingomyelin (SM) and phosphatidylserine (PS). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) accounted for more than 70% of total phospholipids in both groups. A comparison of phospholipid distribution in LS and HS groups demonstrated a higher percentage of PE and a small, but significant, decrease of PC and SM in LS group. The percentage of phosphatidylinositol (PI), PS and cardiolipin (CL) were not affected by mineralocorticoid treatment. With respect to the major phospholipids (PE, PC), a higher level of n-6 polyunsaturated fatty acids (PUFA) and lower levels of monounsaturated fatty acids were detected in PC of LS group. The increase of PUFA predominantly reflected an increase in arachidonic acid by 53%. In comparison to the HS group, oleic acid content was decreased in PC and PE isolated from colonocytes of the LS group. Our data indicate that alterations in phospholipid concentration and metabolism can be detected in rats with secondary hyperaldosteronism. The changes in phospholipid concentration and their fatty acid composition during fully developed effect of low dietary Na+ intake may reflect a physiologically important phenomenon with long-term consequences for membrane structure and function.
在作为盐皮质激素靶组织的大鼠结肠中，研究了低盐饮食对磷脂组成和重塑的影响。为阐明这个问题，雄性Wistar大鼠在检查分离结肠细胞的磷脂浓度和脂肪酸组成之前，分别给予低盐饮食并饮用蒸馏水（LS，低盐组）或饮用盐水而非水（HS，高盐组）12天。饮食方案显著影响醛固酮的血浆浓度，其在LS组中较高而在HS组中几乎为零。皮质酮的血浆浓度未改变。以细胞蛋白含量表示时，除鞘磷脂（SM）和磷脂酰丝氨酸（PS）外，LS组中磷脂浓度显著更高。两组中磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE）占总磷脂的70%以上。LS组和HS组磷脂分布的比较表明，LS组中PE的百分比更高，而PC和SM有小幅但显著的降低。磷脂酰肌醇（PI）、PS和心磷脂（CL）的百分比不受盐皮质激素处理的影响。就主要磷脂（PE、PC）而言，LS组PC中检测到较高水平的n-6多不饱和脂肪酸（PUFA）和较低水平的单不饱和脂肪酸。PUFA的增加主要反映花生四烯酸增加了53%。与HS组相比，从LS组结肠细胞分离的PC和PE中油酸含量降低。我们的数据表明，在继发性醛固酮增多症大鼠中可检测到磷脂浓度和代谢的改变。低膳食钠摄入充分发挥作用期间磷脂浓度及其脂肪酸组成的变化可能反映一种对膜结构和功能具有长期影响的生理重要现象。
