|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1995 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1994 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Compoition of molecular species of phospholipid regulates physical properties of biological membranes and affects signal transduction and formation of eicosanoids in cells. Accordingly, one could regulate physiology ofa particular organ through the control of compositions of molecular species of phospholipids if one has a way to manipulate the composition. In this context, we studied the mechanism for the control of composition of molecular species of phospholipids in organs and obtained the following results.
(1)Clofibric acid increased hepatic concentrations of phosphatidylcholine (PC) by enhancing bioynthesis de novo and of phosphatidylethanolamine (PE) by stimulating a subroute from PC to PE via phosphatidylserine. The metabolic changes induced by clofibric acid in hepatic phospholipids caused marked alterations of composition of molecular species of PC and PE,resulting from concerted effects of changes in composition of molecular speciss of diacylglycerol supplied, stimulation of r
eacylation of PC and PE,and suppression of N-methylation of PE.(2) kidney contained massive dipalmitoy-PC that liver and serum hardly contained, which is an originality of kidney concerning composition of molecular species of PC.(3) Effects of clofibric acid, feeding fat free diet and induction of diabetes on the compositions of molecular species of PC in brain, pancreas and kidney were investigated. No alteration was observed in brain, indicationg that composition of molecular species of phospholipid of brain in under strict control and is independent of changes occurred in serum phospholipid. The composition of molecular species of renal PC was strongly dependent on that of serum PC and the composition of molecular species of pancratic PC depended partially on that of serum phospholipid. Consequently, these results are indicative of the possibility that composition of molecular species of phospholipids can be manipulated by drug (such as clofibric acid) and dietary fatty acids.
(2)腎臓は肝臓や血液のリン脂質にはほとんど認められないジパルミチルPCを de nove 合成し、多量に含むというリン脂質分子種の臓器独自性を有しているが、一方、(3)に記載したように、リン脂質分子種組成の血液依存性の高い臓器でもある。