Hormones metabolic effects

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. 

The thyroid hormones are lipophilic and relatively insoluble in the plasma. Therefore, they are transported throughout the circulation bound to plasma proteins such as thyroxine-binding globulin (75%) and albumins (25%). Approximately 99.96% of circulating thyroxine is protein bound. Bound hormone is not available to cause any physiological effects however, it is in equilibrium with the remaining 0.04% that is unbound. This free form of the hormone is able to bind to receptors on target tissues and cause its effects. Thyroid hormone has many metabolic effects in the body ... 

Table 11.1 Some metabolic effects of insulin. These effects are generally countered by other hormones (glucagon and, in some cases, adrenaline). Hence, the overall effect noted often reflects the relative rates of these hormones present in the plasma...

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. 

For the last forty years, many reports have emerged on the hormone-like effects of chemical compounds such as pesticides and industrial chemicals upon wildlife and humans. The effects of these materials are believed to be either direct or indirect. Direct effects involve positive or negative interactions with the hormone receptors. Indirect effects may result when the synthesis of hormones or their receptors is altered, or the transport, metabolism, or elimination of hormones is modified in some way. The discovery of hormone-like properties of some compounds was made long after their release into the environment. It was shown soon after their introduction that aviation crop dusters handling DDT had low sperm counts and workers at a plant producing the insecticide kepone were reported to have low libido, sperm counts and to be impotent. Subsequently, experiments conducted in laboratory animals demonstrated unambiguously the oestrogenic activity of these pesticides. 9 refs. 

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. 

D) Glucagon is a hormone that counteracts many of the metabolic effects of insulin. 

Mechanism of Action A natural hormone derived from animal sources, usually beef or pork, fhat is involved in normal mefabolism, growfh, and development, especially the central nervous system (CNS) of infanfs. Possesses cafabolic and anabolic effecfs. Provides both levothyroxine and liothyronine hormones. Therapeutic Effect Increases basal metabolic rate, enhances gluconeogenesis, stimulates protein synthesis. 

Haffner D, Nissel R, Wuhl E, Schaefer F, Bettendorf M, Tonshoff B, Mehls O. Metabolic effects of long-term growth hormone treatment in prepubertal children with chronic renal failure and after kidney transplantation. 

Hayakawa M, Shimazaki Y, Tsushima T, Kato Y, Takano K, Chihara K, Shimatsu A, Irie M. Metabolic effects of 20-kilodalton human growth hormone (20k-hGH) for adults with growth hormone deficiency results of an exploratory uncontrolled multicenter clinical trial of 20k-hGH. J Clin Endocrinol Metab 2004 89 1562-71. 

Various hormonal and metabolic effects of aldesleukin are temporally related to hypotension. Transient serum rises in ACTH, cortisol, beta-endorphin, adrenaline and noradrenaline have been found, whereas there were no significant changes in the plasma concentrations of several other hormones (4). 

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