Contenido y Composición de Lípidos Neutros y Polares de Plaquetas Vitelinas de Ovocitos V de Bufo arenarum.

BUSCHIAZZO J; BRUZZONE A; ALONSO TS

Tafí del Valle, Tucumán

Congreso; XVIII Jornadas Científicas, Asociación de Biología de Tucumán; 2001

Asociación de Biología de Tucumán

Yolk platelets are structures situated in the oocyte cytoplasm that may be involved in membrane biogenesis. The lipid characterization of these organelles in stage V oocytes was carried out. Oocytes were manually obtained. Yolk platelet fraction was isolated according to Bonini et al (1981). Lipids were extracted by Folch (1957), separated by thin-layer chromatoghy and derivatized by methanolysis for compositional studies. Methyl esters were identified in a gas-liquid chromatograph. Phosphorus phospholipids and proteins were measured by Rouser (1970) and Lowry (1951), respectively. Phosphatidylcholine and phosphatidylethanolamine (PC and PE) are the main phosphoglycerides followed by phosphatidylinositol (PI), sphingomyeline (SM), phosphatidylserine (PS) and phosphatidic acid (PA). Phosphoglycerides profile is similar to that in whole oocytes except for diphosphatidylglycerol which is a mitochondrial lipid. Yolk platelet fraction is free of mitochondrial contamination. Oleic, palmitic and linoleic acids are the principal fatty acids in PC and PE. PI and PS are enriched in arachidonic acid. In triacylglycerides, palmitic and oleic acids are the majors followed by linoleic acid. In diacylglycerides, palmitic acid is the main component as in free fatty acid fraction. The three neutral lipid clases show a similar unsaturation index.