Hormones metabolism

Few studies have been conducted on other invertebrate taxa but pentach-lorophenol exposure has been shown to affect daphnid reproductive capacity and sex steroid hormone metabolism and a high incidence of intersex has been observed in harpacticoid copepods near an Edinburgh sewage outfall. " ... 

Brouwer, A. (1991). Role of biotransformation in PCB-induced alterations in vitamin A and thyroid hormone metabolism in laboratory and wildlife species. Biochemical Society Transactions 19, 731-737. 

As noted above, many of the AEDs induce hepatic microsomal enzyme systems and thus reduce the effectiveness of hormonal contraceptives. Women taking AEDs that may reduce the effectiveness of hormonal contraceptives should be encouraged to also use other forms of birth control. Due to induction or inhibition of sex hormone metabolism and changes in binding of hormones to sex hormone binding globulin, some AEDs may reduce fertility. For example, valproate has been associated with a drug-induced polycystic ovarian syndrome. Women who experience difficulties with fertility should seek the advice of health care professionals with expertise in fertility. 

Engelsma, G. In "Regulation of Secondary Product and Plant Hormone Metabolism" Luckner, M. Schreiber, K., Eds. Pergamon New York, 1979 pp. 163-72. 

D23. Docter, R., Krenning, E. P., de Jong, M., and Hennemann, G., The sick euthyroid syndrome Changes in thyroid hormone serum parameters and hormone metabolism. Clin. Endocrinol. 39, 499-518 (1993). 

The balance between excess and insufficient zinc is important. Zinc deficiency occurs in many species of plants and animals, with severe adverse effects on all stages of growth, development, reproduction, and survival. In humans, zinc deficiency is associated with delayed sexual maturation in adolescent males poor growth in children impaired growth of hair, skin, and bones disrupted Vitamin A metabolism and abnormal taste acuity, hormone metabolism, and immune function. Severe zinc deficiency effects in mammals are usually prevented by diets containing >30 mg Zn/kg DW ration. Zinc deficiency effects are reported in aquatic organisms at nominal concentrations between 0.65 and 6.5 pg Zn/L of medium, and in piscine diets at <15 mg Zn/kg FW ration. Avian diets should contain >25 mg Zn/kg DW ration for prevention of zinc deficiency effects, and <178 mg Zn/kg DW for prevention of marginal sublethal effects. 

TCDD also causes thyroid tumours in male rats. This has been shown to proceed through a mechanism that involves altered thyroid hormone metabolism and consequent increases in feedback mechanisms, TSH (thyroid stimulating hormone), which results in a chronic proliferative stimulation of thyroid follicular cells. 

Sterol biosynthesis Bile acid biosynthesis C2rSteroid hormone metabolism Androgen and estrogen metabolism Nucleotide Metabolism Purine metabolism Pyrimidine metabolism Nucleotide sugar metabolism Amino sugar metabolism Amino Acid Metabolism Glutamate metabolism Alanine and aspartate metabolism Glycine, serine, and threonine metabolism... 

Three dietary intervention studies reported the effects of soy or soy phytoestrogen consumption on reproductive hormones in men and very modest alterations of doubtful clinical significance were found (Habito et al., 2000 Nagata et al., 2001). None of these studies evaluated the prostate itself, and it is possible that soy consumption alters local hormone metabolism and action within the gland. 

Donath J, Boland W (1994) Biosynthesis of acyclic homoterpenes in higher plants parallels steroid hormone metabolism. J Plant Physiol 143 473 78... 

The steroid hormones are mainly inactivated in the liver, where they are either reduced or further hydroxylated and then conjugated with glucuronic acid or sulfate for excretion (see p. 316). The reduction reactions attack 0X0 groups and the double bond in ring A. A combination of several inactivation reactions gives rise to many different steroid metabolites that have lost most of their hormonal activity. Finally, they are excreted with the urine and also partly via the bile. Evidence of steroids and steroid metabolites in the urine is used to investigate the hormone metabolism. 

A myriad of cardiovascular, respiratory, hormonal, metabolic, and neuropsychic responses, which can be caused by adrenergic drags, are generally very similar to many of the adaptive reactions of the organism such as increased physical activity and physical stress. 

An adequate dietary intake of iodine is essential to prevent hypothyroidism. In many areas of the world, dietary iodine intake is insufficient and must be supplemented. There is another element in which a dietary intake may be insufficient that is also associated with thyroid hormone metabolism. This element is... 

B. Selenium in the form of selenocysteine is required for three enzymes that remove iodide from thyroid hormones. There are no signihcant areas in which dietary intake of sodium or potassium are problems. Fluorine deficiency is not associated with thyroid hormone metabolism. 

Byme JJ, Carbone JP, Hanson EA. 1987. Hypothyroidism and abnormalities in the kinetics of thyroid hormone metabolism in rats treated chronically with polychlorinated biphenyl and polybrominated biphenyl. Endocrinology 21 520-527. 

Ohnhaus EE, Studer H. A link between liver microsomal enzyme activity and thyroid hormone metabolism in man. Br J Clin Pharmacol 1983 15(l) 71-6. 

Thyroid function tests are often altered by somatropin because of increased conversion of T4 to T3, but this is clinically insignificant at low doses (SEDA-21, 453). One child with Prader-Willi syndrome had a fall in serum thyroxine concentration during somatropin therapy and needed thyroxine replacement (33). Hypothyroidism developed in 11 of 46 growth hormone-deficient children treated with somatropin (34). Prior abnormalities in hypothalamic-pituitary function and alterations in thyroid hormone metabolism, probably both, contributed to the high incidence of hypothyroidism, which was similar to that in previous studies. 

The effect of beta-adrenoceptor antagonists on thyroid hormone metabolism is unlikely to play a significant role... 

Cushing s syndrome, gynecomastia, amenorrhea, and precocious puberty have been regarded as reflecting the enzyme-inhibitory activity of isoniazid, with resulting derangement of hormone metabolism in the liver. 

Wiersinga WM, Trip MD. Amiodarone and thyroid hormone metabolism. Postgrad Med J 1986 62(732) 909-14. 

Laurberg P, Andersen S, Karmisholt J. Cold adaptation and thyroid hormone metabolism. Horrn Metab Res. 2005 37 545-549. 

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