Hormonal Pyridoxine

Be Pyridoxine, pyridoxal, pyridoxamine Coenzyme in transamination and decarboxylation of amino acids and glycogen phosphorylase role in steroid hormone action Disorders of amino acid metabolism, convulsions... 

Uterine fibroids Preexisting uterine leiomyomata (uterine fibroids) may increase in size. However, there is no evidence of this with low-dose hormonal contraceptives. Depression The incidence of depression in OC users ranges from less than 5% to 30%. Pyridoxine deficiency may be a factor in the depression. Women who become significantly depressed when using hormonal contraceptives should stop the... 

The hypothalamus contains high concentrations of the monoamines dopamine and serotonin and these neurotransmitters have inhibitory or excitatory effects, respectively, on the anterior pituitary. For example, thyroid-stimulating hormone (TSH) secretion is increased by serotoninergic and decreased by dopaminergic activation. Pyridoxine deficiency in rats is associated with low levels of PLP in the hypothalamus, with no change in dopamine concentrations, but decreased levels of serotonin (Dakshinamurti et al., 1990). This correlates with decreased thyroid status and decreased pituitary TSH. Treatment with pyridoxine returns these parameters to normal. 

Other endocrine sy.stems are interrelated. Both cortico.stc-roids and thyroid hormones may increase the requirement for pyridoxine and affect pyridoxal S-phosphate-dependent metabolic processes. Moreover, there appear to be associations between vitamin B<, and anterior pituitary hormones that seem to involve the hypothalamus, S-hydroxytryptamine, and dopamine. The latter two neurolransmitters are synthesized by metabolic proce.sse that require pyridoxal S-phu.sphate. 

Most vitamins function either as a hormone/ chemical messenger (cholecalciferol), structural component in some metabolic process (pantothenic acid), or a coenzyme (phytonadi-one, thiamine, riboflavin, niacin, pyridoxine, biotin, folic acid, cyanocobalamin). At least one vitamin has more than one biochemical role. Vitamin A as an aldehyde (retinal) is a structural component of the visual pigment rhodopsin and, in its acid form (retinoic acid), is a regulator of cell differentiation. The precise biochemical functions of ascorbic acid and a-tocopherol still are not well defined. 

Other fractions of the vitamin B complex have also been tested for their effect on the survival of young adrenalectomized rats, and it was found that biotin was as effective as pantothenate (Ralli and Dumm, 1952). This is interesting in view of the previous discussion of the interrelation of biotin and pantothenic acid (see Section V.b). In this same series of experiments it was observed that large doses of pyridoxine were toxic to adrenalectomized rats when given after a period of pantothenate deficiency. Thiamine and riboflavin had no influence on survival, but folic acid and vitamin Bu resulted in a moderate improvement. These observations emphasize the interaction of vitamins under various nutritional situations in relation to hormone action. 

In rats fed a diet adequate in vitamin Bg, the fraction of total pyridoxal phosphate found in the nuclei of liver cells was 21%, and this increased to 39% in rats fed a vitamin Bg-deflcient diet, indicating a conservation of the vitamin in the nuclear compartment during deficiency. Pyridoxal phosphate in the cell nucleus is protein bound, and this protein has an apparent molecular mass of 50 to 55 kDa. Cells grown in the presence of 5 mM pyridoxine have a decreased glucocorticoid-dependent induction of enzymes such as tyrosine aminotransferase. Vitamin Bg regulates transcriptional activation of human glucocorticoid receptors in the HeLa cells. The modulatory role in transcription is not restricted to the glucocorticoid receptor but extends to other members of the steroid hormone super family. The intracellular concentration of PLP could have a profound influence on steroid hormone-induced... 

Axelrod, A. E. and Trakatellis, A. C. (1964) Relationship of pyridoxine to immunological phenomena, Vitamins and Hormones,... 

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