A study on the lipids of Ascaris suum ova

ABSTRACT

The present study was undertaken to observe the quality and quantity of lipid constituents by the developing Ascaris suum eggs. The collected eggs from the uterus of A. suum were classified into 3 groups, i.e., single cell stage, morula stage and embryonated eggs, and were subjected to analyse their lipid fractions. To obtain the morula stage eggs, 10 to 11 incubation days at 30 degree C were needed and for the embryonated eggs, 30 to 31 days were lasted. At the time of experiment, their indices of development by Hoffman were 285(morula stage) and 42 (embryonated stage) respectively. Lipid extraction was done by the methods of Folch et a1. (1957) and Kenny (1952), and then the extracted lipid fractions from the above 3 groups of eggs were separated by thin layer chromatography. Those fractions were also subjected to perform the quantitative analyses of fatty acids, glycerides, cholesterol and phospholipids. The results obtained were summarized as follows. Total amount of fatty acid was decreased from 12.9 mg per gram of eggs (single cell stage) to 6.6 mg/gm (embryonated eggs), whereas the proportion of free fatty acid to total fatty acid was constantly increased from 77.5 percent to 89.4 percent during the period of egg development. Total amount of glycerides was also increased from 33.0 mg/gm of single cell stage to 55.9 mg/gm of the embryonated eggs. The most abundant glyceride among 3 glycerides discovered from A. suum eggs was triglyceride, and the least was monoglyceride. The amount of free cholesterol was much larger than that of ester form in general, and it reached maximum in the eggs of morula stage (4.6 mg/gm). The increase of total cholesterol was monitored during the development of A. suum eggs from 3.3 mg/gm to 5.4 mg/gm. The following 8 phospholipids were detected in the embryonated eggs, i.e., lysophosphatidyl choline, phosphatidyl inositol, sphingomyelin, phosphatidyl choline, phosphatidyl glycerol, phosphatidyl serine, phosphatidyl ethanolamine and unknown phospholipid. But in the single cell stage eggs, 4 kinds out of the above 8 phopholipids were not observed, and in the morula stage eggs, 2 kinds were absent among the 8 phospholipids.