[Vitamin A and lipid peroxidation: effect of retinol deficiency]

The effect of alimentary vitamin A deficiency on some parameters of lipid peroxidation (LPO) in young rats was studied. It was found that under vitamin A deficiency the content of diene conjugates in liver homogenates and microsomes diminishes, whereas that of malonic aldehyde in small intestinal mucosa, liver and testis homogenates is unaffected. However, the malonic aldehyde production in liver homogenates and microsomes decreases after 60 min incubation at 37 degrees C without addition of prooxidants. At the same time, enzymatic NADPH-dependent and nonenzymatic ascorbate-dependent LPO in liver microsomes of vitamin A-deficient rats does not change significantly. The decrease of LPO intensity in vitamin A-deficient animals may be due to the reduced content in liver microsomes of the main LPO substrates, i.e., arachidonic and linoleic acids, as well as to the decrease of cytochrome P-450 level in rat liver.