title: Reduction of ceramide de novo synthesis in solid tissues changes sphingolipid levels in rat plasma, erythrocytes and platelets.
abstract: OBJECTIVE
  De novo sphingolipid synthesis does not occur in plasma, erythrocytes and platelets. The purpose of the study was to examine the effect of inhibition of sphingolipid synthesis in solid tissues on the level of the following bioactive sphingolipids: sphinganine, ceramide, sphingosine and sphingosine 1-phosphate in plasma, erythrocytes and platelets.
  
  
  METHODS
  The experiments were carried out on male Wistar rats. Myriocin was used to inhibit serine palmitoyltransferase activity (the enzyme catalyzes the first step of ceramide de novo synthesis) and nicotinic acid was used to reduce the concentration of plasma free fatty acids (a substrate for the de novo ceramide synthesis). The sphingolipids were quantified by means of liquid chromatography/mass spectrometry.
  
  
  RESULTS
  Myriocin reduced the level of each compound in plasma. It reduced the level of sphinganine, sphingosine-1-phosphate and total ceramide and elevated the level of sphingosine in erythrocytes. In platelets, myriocin reduced the total level of ceramide. Nicotinic acid reduced the plasma level of sphinganine, sphingosine and total ceramide. It increased the level of sphingosine-1-phosphate in erythrocytes. In platelets, nicotinioc acid increased the level of sphinganine and sphingosine and reduced the level of sphingosine-1-phosphate and total ceramide.
  
  
  CONCLUSIONS
  Inhibition of serine palmitoyltransferase activity in solid tissues and reduction in plasma free fatty acids concentration affects sphingolipid level in plasma, erythrocytes and platelets. The changes in erythrocytes and platelets depend both on the cell type and the sphingolipid studied and only partially follow the changes in the plasma.
authors.affiliation: Department of Physiology, Medical University of Bialystok, Bialystok, Poland. Electronic address: agnieszka.blachnio@umb.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Błachnio-Zabielska
authors.affiliation: Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Baranowski
authors.affiliation: Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Wójcik
authors.affiliation: Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Górski
mesh_terms: D000818:Animals; D053898:Biosynthetic Pathways / Q000187:drug effects; D001792:Blood Platelets / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005227:Fatty Acids / Q000097:blood; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D008297:Male; D009525:Niacin / Q000494:pharmacology; D009928:Organ Specificity / Q000187:drug effects; D017208:Rats, Wistar; D013107:Sphingolipids / Q000097:blood*
chemical_list: D002518:Ceramides; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D013107:Sphingolipids; D009525:Niacin; C001996:thermozymocidin
keywords: Erythrocytes; Myriocin; Plasma; Platelets; Sphingolipids