[The fatty acids of trichinellae]

The composition of fatty acids of lipids in the muscles of rats and larvae of Trichinella spiralis and T. nativa developing in them were studied. Both species are characterized by practically the same composition of fatty acids, only in the frost-resistant species T. nativa there was a sufficient amount (up to 3.5%) of docosapenta- and docosahexaenic acids (22:5 and 22:6). The comparison of the content of individual fatty acids in larvae and in muscles of the host by means of statistical correlation analysis suggests that larvae obtain a considerable portion of palmitic acid from the host and transform in into necessary long-chain saturated and unsaturated fatty acids by means of elongating and desaturating enzymes. Changes in the contents of fatty acids in larvae extracted from dead rats, which during some days were undergone freezing at negative temperatures (-8-10 degrees), are the same in quality for both species. These changes can be explained if we assume that the activity of elongases and desaturases of Trichinella decreases with cooling to a greater extent than the supply of palmitic acid from the host's tissues. A higher frost-resistance of T. nativa may be associated as with a greater protection of enzymes in the membranes by long-chain polyene acyls so with a higher thermal stability of proteins themselves.