Effect of Long-Term Light Deprivation on α-Tocopherol Content in Rats during Ontogeny.

We studied the effect of long-term light deprivation which began at different stages of ontogeny on the content of α-tocopherol in rats during the first 3 months of postnatal development. In the offspring postnatally exposed to constant darkness, the level of α-tocopherol in the liver, kidneys, heart, skeletal muscles, and lungs was significantly decreased at the early stages of postnatal ontogeny (2 weeks and 1 month). In rats kept under constant darkness after birth, the content of α-tocopherol in the lungs was also reduced at the age of 1 month. The modulating effect of light deprivation on the level of α-tocopherol can be associated both with the impact of disturbed circadian rhythms and with increased content of melatonin in the body.

[Species-specific features of tocopherol content in carnivorous mammals during autumn period].

A comparative study of the major liposoluble antioxidant, vitamin E (α-tocopherol), content was conducted in carnivorous mammals (polar fox, silver fox, raccoon dog, mink, sable) during late autumn under natural lowering of temperature. The highest vitamin E content in liver and kidney was found in polar fox and raccoon dog, obviously due to seasonal metabolic changes and ecological specialization determining the accumulation of considerable amounts of tocopherol both in polar and hibernating species. To investigate the features of vitamin E accumulation, the tocopherol loading experiment was implemented on three species (polar fox, silver fox, mink). It was shown that polar fox, as compared to silverfox and mink, exhibits a higher ability to reserve vitamin E. The established differences in tocopherol content and distribution in different species should be considered as a genetically fixed reaction to the effect of environment underlain by metabolic differences in animals with different ecological specialization. The ability of tocopherol to accumulate in tissues and organs allows considering its essential role in stabilization of the antioxidant system and ensuring thereby a seasonal cold resistance.

[Influence of prenatal and postnatal illumination on male rat physiologycal parameters].

Influence of different light conditions on some physiological parameters of 3-month old male rats was studied. It was established that influence of constant light on mothers during pregnancy or on their posterity from birth leads to one-way changes of the antioxidant system, isoenzymatic spectrum of lactate dehydrogenase, blood indices and leucogram. However, the reaction is different and depends on moment of exposure. The results of testicular development of male rat indicate less sensitivity to light condition in the prenatal period compared to the postnatal ontogenesis.