The aim of this investigations was to study the effect of a short time
medium-chain triacylglycerols diet (MCTD) on the lipids (particularly
of fatty acids) of the rat kidney. During 14 days, two groups of rats
(Fischer strain) were fed a MCTD (18.7% MCTs, 16.5 kJ/g dry matter) o
r an isoenergetic control diet (standard rat chow). Total lipids were
isolated and separated into particular lipid classes by thin-layer chr
omatography. No essential differences in the distribution of analyzed
lipids (cholesterol, cholesterol ester, tracylglycerols, free fatty ac
ids, phosphatidylcholine, phosphatidylethanolamine and sphingomyeline)
were noticed after MCTD. The results showed no changes in the concent
ration of total neutral lipids, but slight changes appeared in the con
centration of particular classes of neutral lipids. Concentrations of
cholesterol and cholesterol ester were decreased by approximately 14%
by MCTD feeding and, at the same time, the concentration of triacylgly
cerols, free fatty acids and esters of fatty acids was increased by 4%
. The ratio of free cholesterol to total phospholipids (C/P) decreased
(17%) after MCTD. The data indicate a significant increase in fatty a
cid saturation (expressed asa saturation factor (S-f)) affected by MCT
D. Both of the mentioned data (C/P ratio, Sc), as well as' some additi
onal ones reported in this paper, suggest that MCTD can affect the mem
brane fluidity, although at present it is not possible to judge whethe
r or not such effects could change the physiological function of the k
idney.