Transformation of sterols pattern in course of late development of rat brain.

Free sterol content was determined in the late period of development of the rat brain using the method of gas chromatography-mass spectrometry. The results obtained have shown that the free sterol pattern is very unstable in course of late period of ontogenic development. In contrast to young adult rats, in which apart from cholesterol only trimethylcholestenon and trace amounts of desmosterol were visible, in the brain of 1 and 2 years old rats some new sterols are appearing. There are cholestadien, cholest-5-en-3-on, 4 methyl-cholesten, cholest-5-en-3-ethoxy and 4,4,14-trimethyl-5-alpha-cholest-24-en-3-en. There are also qualitative differences in the structure of some sterols (various isomers) between both groups of late development. These changes, indicating some transformation of cellular membranes seem to be the result of biologically programmed late ontogenic development.