The purpose of the study is to find out the effects of vitamin E (α-tocopherol) on hypothalamic-pituitary-testicular system in white male rats.
Vitamin E (α-tocopherol, or α-T) was given per os to the animals during 2 weeks at the daily dose of 2 mg per 100 g of the animal weight. After that the indexes of the functional condition of the testes, pituitary gland and hypothalamus were studied. The vitamin mentioned decreases the indexes of peroxidating hemolisis of erythtrocytes which reflects the level of lipid peroxidation processes in blood, the processes determing after all the functional possibilities in living systems and their physiological status.In testicular tissue the level of hydroperoxides decreases as well as the content of malonic dialdehyde, one of the products of lipid peroxidation. The tendency of decreasing of reduction-oxidation potential (redox-potential, RP, or ROP) dealing with the testicular tissue takes place which also tells us about decreased level of oxidation products as a result of antioxidant properties of α-tocopherol. Moreover, vitamin E has been found to stimulate relative testes weight increasing compared to the control (P<0.05). The increasing is 16.5%. The vitamin introduction causes testosterone level increasing in blood from 1.415 up to 1.702 ng/cm3. At the same time the lutropin level has been found to be more than twice as much as in the control group (P<0.001) which is in accordance to positive correlation coefficient ( r = + 0.948; P<0.001 ), which deals with testosterone and lutropin levels. In addition to this the relative weight of the pituitary gland has been 23% more than in the control (P<0.05).This fact explains the improvement of the pituitary gland function reflected by the increased level of luteinizing hormone. As a result the testosterone level has been found to be increased. On the one hand it is the pituitary gland that determines the functional condition of the testes. On the other hand, however, it is possible for vitamin E to stimulate the testes functional activity directly taking into account the histological data of the testicular tissue.On histological microscopic sections of testicular tissue we´ve found widening of spermatogenic epithelium and increased diameters of semineferous pathways under the influence of α-tocopherol. The interstitial tissue mass has been found to be increased twice compared to the control. The increased mass has been due to proliferation of Leydig´s cells of average size population. The volume of the cells has proved to be nearly twice as big as in the control group (P<0.05). It is the average size population of Leydig´s cells that is generally responsible for testosterone secretion, and Leydig´s cells of such kind are functionally active. It has been discovered that ROP of homogeneous mixture of the mediobasal hypothalamus is 25% less, compared to the control (P<0.01) that points to the fact of the functional activity improving of this hypothalamic region which is responsible, in particular, for reproductive processes. The obtained results dealing with functional activity improving of mediobasal hypothalamus are in accordance to the works by Teply D.L. (1990) who studied the influence of vitamin E (α-tocopherol) on morphometric indexes of functional conditions of hypothalamic centres, in particular suprachiasmatic and arcuate nuclei located within the mediobasal hypothalamus.
Thus, the mentioned above influence of vitamin E (α-tocopherol) improves the functional activity of the hypothalamic-pituitary-testicular complex in the rats in general. As the pituitary gland and the testes are rich in vitamin E, it can be an indirect evidence of the vitamin participation in synthesis and excretion of adenohypophysis hormones and testosterone. The effect of vitamin E (α-tocopherol) on hypothalamus is accompanied with spectacular changes of its functional activity in accordance to the level of oxidation products. After all it determines the changes of the hormone activity of the pituitary-testicular complex.
Библиографическая ссылка
Loginov P.V. THE EFFECT OF VITAMIN E (Α-TOCOPHEROL) ON FUNCTIONAL CONDITION OF HYPOTHALAMIC-PITUITARY-TESTICULAR COMPLEX IN WISTAR MALE RATS // Современные наукоемкие технологии. – 2005. – № 7. – С. 50-51;URL: https://top-technologies.ru/ru/article/view?id=23389 (дата обращения: 21.11.2024).