Experimental nephrotic syndrome induced in the rat by puromycin aminonucleoside: Hepatic synthesis of neutral lipids and phospholipids from3H‐water and3H‐palmitate

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Abstract
Experimental nephrotic syndrome (ascites, proteinuria, hypoalbuminemia, and hyperlipidemia) was induced in male Wistar rats by seven daily subcutaneous injections of puromycin aminonucleoside (20 mg/kg). Hepatic lipogenesis from3H‐water and3H‐palmitate was investigated in nephrotic and pair fed control rats by using liver slices. Total incorporation of3H‐water into neutral lipids was higher in nephrotic than in control rats (413±124 vs. 229±46 nmoles/g/hr, p<.01). Among neutral lipids, the major increase was observed for triacylglycerols (106±26 vs. 72±21 nmoles/g/hr, p<.05), cholesteryl esters (3.7±2.1 vs. 1.4±.7 nmoles/g/hr, p<.05) and, above all, for cholesterol (123 ±48 vs. 36±18 nmoles/g/hr, p<.0025). Total incorporation of3H‐water into phospholipids as well as incorporation of3H‐water into individual phospholipids were not significantly increased. Incorporation of3H‐palmitate into neutral lipids was increased (312±84 vs. 221±28 nmoles/g/hr, p<.05). Among neutral lipids, a significant increase was observed for 1,3‐diacylglycerols (19±3 vs. 13±3 nmoles/g/hr, p<.025), triacylglycerols (228±50 vs. 163±14 nmoles/g/hr, p<.05) and cholesteryl esters (18±5 vs. 10±1 nmoles/g/hr, p<.01). Incorporation of3H‐palmitate into phospholipids was not significantly affected. The difference in hepatic lipogenesis between nephrotic and control rats was even more pronounced if the data were corrected for the total liver weight which was significantly increased in the nephrotic rats (11.3±.3 vs. 8.5±.1 g, p<.001). These findings indicate that the synthesis of neutral lipids from both3H‐water and3H‐palmitate is elevated in rat with aminonucleoside‐induced nephrotic syndrome. The possible role of the increased hepatic lipogenesis in the pathogenesis of the nephortic hyperlipidemia is discussed.