Cytochrome p450 steroid hormone biosynthesis

In a review article on “Drug Metabolism and Variability among Patients in Drug Response” published in the New England Journal of Medicine , Wilkinson (2005) stated that “there have not yet been prospective clinical trials showing that knowledge of a patient’s genotypic profile before prescribing drugs either increases drug efficacy, prevents or reduces adverse drug reactions, or lower the overall costs of therapy and associate sequelae …. For now, however, the individual patient is probably best served by an alert physician aware of the possibility that a genetic polymorphism in drug metabolism may be a potential factor in unexpected drug response”.

Apparent combined P450C17 and P450C21 deficiency (see 613571) is a rare variant of congenital adrenal hyperplasia, first reported by Peterson et al. (1985). Affected girls are born with ambiguous genitalia, indicating intrauterine androgen excess. After birth, however, virilization does not progress and amounts of circulating androgens are low or normal. Affected boys are sometimes born undermasculinized. Boys and girls can also present with bone malformations. Findings of biochemical investigations of urinary steroid excretion in affected patients have shown accumulation of steroid metabolites, indicating impaired C17 and C21 hydroxylation, suggesting concurrent partial deficiencies of the 2 steroidogenic enzymes, P450C17 and P450C21. However, sequencing of the genes encoding these enzymes showed no mutations, which accorded with the idea of a defect in a cofactor that interacts with both enzymes.

Contraindications
While there has been no definite information published as to who should not take pregnenolone, on theoretical grounds, a few cautions can be suggested. Since pregnenolone (especially at high doses) may (in some people) increase estrogen or testosterone levels, I believe that men with prostate cancer (which may be worsened by testosterone) and women with breast or ovarian cancer (which may be worsened by estrogen) should probably take pregnenolone only with their doctors consent and supervision. Men with high PSA (prostate specific antigen) blood levels (possible indicator for undiagnosed or future prostate cancer) should also proceed with caution with pregnenolone use. Lastly, because of pregnenolones anti-GABA, pro-NMDA action, persons known to suffer from epileptic seizures or who are taking an anti-seizure medication such as Dilantin, Depakote or Tegretol should probably only use pregnenolone with their doctors supervision. Finally, as we age, the body produces ever-less of the enzyme which converts pregnenolone to DHEA. Thus, while supplementary pregnenolone taken during middle age and beyond will produce at least some normalization back toward more youthful (and healthful) levels of other steroid hormones, pregnenolone will not completely substitute for other steroid hormone supplements in those with medically demonstrated needs for various specific steroids ., DHEA, cortisol, estrogen, etc.
 

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

Cytochrome p450 steroid hormone biosynthesis

cytochrome p450 steroid hormone biosynthesis

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

Media:

cytochrome p450 steroid hormone biosynthesiscytochrome p450 steroid hormone biosynthesiscytochrome p450 steroid hormone biosynthesiscytochrome p450 steroid hormone biosynthesiscytochrome p450 steroid hormone biosynthesis