Studies on the Relationship of Vitamin E (Tocopherols) to the Endocrine System

Abstract

Although it is now established that deprivation of vitamin E may lead to disturbances of structure and function of many tissues other than those primarily concerned in the reproductive cycle, it is not surprising, when the striking nature of the testicular degeneration and the curious character of the typical resorption in the female are borne in mind, that there has been a tendency to concentrate attention on the question whether the vitamin plays an essential part in the reproductive cycle.The most direct approach has been made by investigating whether the vitamin itself exerts a gonadotrophic action. Up to the present the evidence has been inconclusive. The most striking claim is that of Szarka [1929], who stated that oral or parenteral administration of vitamin E concentrates produces oestrus in immature female rats. Later, Verz\l=a'\r [1931] recorded that injection of similar materials produced hypertrophy of the uterus in similar animals, but not after ovariectomy. Diakov and Krizenecky [1933 a] as well as Lesbouyrie, Berthelon, and Bajé [1937] were, however, unable to confirm Szarka's and Verzár's findings. Recently, Underhill [1939] has supported the view that vitamin E preparations exert gonadotrophic activity when injected into immature female mice, whereas Demole [1939] did not observe any effect on the reproductive system when doses of a-tocopherol as large as 0-5 g. per kg. were given.It will be recalled that Verzár's belief was that vitamin E is concerned in the formation of one or more of the hormones of the anterior pituitary [Verzár, 1931 ;Verzár, Arvay, and Kokas, 1931 ;Verzár and Kokas, 1931]. The Suggestion that pituitary function is depressed in the condition of vitamin E deprivation was rejected by Evans [1932] because parenteral administration of fresh hypophyseal substance failed to prevent the typical résorption in -deficient females and also because the striking contrast between the severity of the degeneration of testicular structure and the maintenance of normal ovarian structure was incompatible with the accepted views of pituitary function.The pituitary came into the picture again, however, when Nelson [1933] found that testicular degeneration in the condition of E-deficiency is

THE OESTROGENIC INACTIVITY OF dl-α-TOCOPHEROL ACETATE

“…This is in sharp contrast to the still more recent findings of Drummond, Noble & Wright [1939], who injected 5 mg. of 07-a-tocopherol acetate (in 25 mg. of olive-oil solution) daily for five days into immature female rats, whose vaginae were still closed on the subsequent day, and whose ovaries and uteri remained in the infantile condition. Oral administration of vitamin E concentrates to hypophysectomized adult females also failed, in the hands of these authors, to bring about oestrus or pro-oestrus.…”

Lipofuscin Distribution and Histological Lesions in the Vitamin E Deficient Cotton Rat (<i>Sigmodon hispidus hispidus</i>)

“…These pigment deposits have been seen in long term vitamin E deficient rats who displayed regular estrus and normal mating behavior, implying that changes in the pituitary and adrenal are secondary phenomena rather than primary. Drummond et al (1939) indicated that tocopherol has no gonadotropic effects. They administered vitamin E to immature female rats and hypophysectomized adult females and observed no estrogenic effect on ovaries or uterus.…”