Altered plasma levels of lysophospholipids in response to adrenalectomy of rats.

The aim of this study was to investigate effects of reduced stress hormone by adrenalectomy on rat plasma levels of lysophosphatidic acid (LPA) and other lysophospholipids. We measured activities of lysophospholipase D (lysoPLD) in plasma and lipid phosphate phosphatase (LPP) in blood by determining choline and inorganic phosphate, respectively. LPA, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI), lysophosphatidylserine (LPS) and lysophosphatodylglycerol were quantified by LC-MS/MS. In adrenalectomized rats, plasma levels of LPA, LPE, LPS and LPI, but not LPC, were increased. The increased level of LPA were due to decreased LPC level, increases plasma activity of lysoPLD toward LPC and decreased LPP activity toward LPA. Daily injections of deoxycoricosterone into rats selectively reversed increased level of LPS. Our results suggest enzymatic mechanism for increased plasma level of LPA, and indicate that the circulating levels of lysophospholipids including LPA in rats are differently affected by artificial suppression of release of adrenergic hormones.

Alterations of plasma levels of lysophosphatidic acid in response to fasting of rats.

The aim of this study was to investigate the effect of fasting on in vivo plasma levels of lysophosphatidic acid (LPA), a physiologically important lysophospholipid mediator. We assayed to measure activities of an LPA-producing enzyme (lysophospholipase D) and LPA-degrading enzyme activities (lysophspholipase A, lipid phosphate phosphatase) in rat plasma or blood, by measuring choline, fatty acid and inorganic phosphate, respectively. Both LPA and its precursor lysophosphatidylcholine (LPC) were quantified by liquid chromatography-tandem mass spectrometry. Fasting of rats for 24 h decreased plasma concentrations of oleoyl-, linoleoyl-, arachidonoyl- and docosahexaenoyl-LPAs, but not palmitoyl- and stearoyl-LPAs, possibly due to decreased levels of corresponding LPCs in the plasma and elevated lipid phosphate phosphatase activity for LPAs in the blood. Our results indicate that the in vivo circulating levels of LPAs in rats are affected by fasting.

Coronary arterial malformation depicted at multi-slice CT angiography.

We present a case of a 57-year-old woman with an unremarkable medical history except for a continuous cardiac murmur at the left second and third interspaces. Transthoracic echocardiography revealed an unusual chamber in front of the heart. To evaluate the precise anatomy of this abnormality, multi-slice computed tomographic (MSCT) imaging was performed. MSCT angiography with retrospective ECG gating showed a coronary arterial malformation with fistulous communications to the coronary artery, pulmonary artery and the root of aorta. Images from MSCT coronary angiography can be helpful in understanding the tortuous configuration of the coronary arterial malformation.