Effect of increasing age on tissue dolichol levels in ad libitum fed and food-restricted rats.

In order to test the hypothesis that the ageing-related alteration in membrane lipids might reflect the biological age of rodents, we studied the effects of age in ad libitum fed (AL) and food-restricted (FR) male Sprague-Dawley rats on the levels of dolichol in different organs involved [liver (L) and kidney (K)] or not involved [brain (B), sciatic nerve (SN), heart (H), soleus (S) and extensor digitorum longus (EDL) muscles] in dolichol excretion. At the given age, tissue dolichol was extracted and assayed by HPLC procedure. Results show that the levels of dolichol were significantly different in different tissues and increased dramatically with increasing age. The anti-ageing FR regimen had significant preventive effects on dolichol accumulation in the excretory organs. The effect of FR on the liver was much bigger than that of kidney. The effect of FR retarding dolichol accumulation in the liver co-varied with the effects of FR on longevity. In conclusion, these data show that the quantity of dolichol in the hepatic tissue might be used as a marker of the biological age of the animal.