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Nathan Goodyear

Associations between serum phthalates and biomar... [Environ Int. 2014] - PubMed - NCBI - 0 views

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    Phthalates have both central inhibition and peripheral effects. This article highlights the peripheral anti-androgen effects of phthalates and phthalate metabolites. 
Nathan Goodyear

Phthalate-Induced Pathology in the Foetal Testi... [Reproduction. 2013] - PubMed - NCBI - 0 views

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    This study found a 2 fold increased in estradiol levels in rats exposed to phthalates in-utero.  This could have been due to increased aromatase activity and/or xenoestrogenic effect.  This study proposes a link between phthalate exposure in-uteruo, increased estrogen production and testicular dysgenesis syndrome.  Take home: in this model male testicles were altered prior to birth by phthalate exposure.
Nathan Goodyear

Urinary concentrations of di(2-ethylhexyl) phthalat... [J Androl. 2011] - PubMed - NCBI - 0 views

  • three metabolites of DEHP [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP)] were inversely associated with the free androgen index (FAI = T/SHBG) and calculated free testosterone (FT)
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    analysis of 3 urinary phthalate metabolites found to be associated with low free androgen index and a low free Testosterone
Nathan Goodyear

PHTHALATES AND HUMAN HEALTH -- Hauser and Calafat 62 (11): 806 -- Occupational and Envi... - 0 views

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    Phthalates and health effects.
Nathan Goodyear

Urinary Phthalate Metabolites Are Associated With Decreased Serum Testosterone in Men, ... - 0 views

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    Phthalate exposure is a cause of low Testosterone in men, women, and children.   In boys 6-12, exposure was associated with a 24-34% reduction in Testosterone.
Nathan Goodyear

Benzyl butyl phthalate induces epigenetic stress to enhance adipogenesis in mesenchymal... - 0 views

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    Phthalates effect genetic expression of fat prior to birth.  This is science, not politics.
Nathan Goodyear

Urinary bisphenol A, phthalates, and couple fecundity: the Longitudinal Investigation o... - 0 views

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    Study finds phthalate exposure associated with a 20% decline in fertility in men not women.
Nathan Goodyear

Environmental Health Perspectives: Relationship between Urinary Phthalate and Bisphenol... - 0 views

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    Phthalate and Bisphenol A interferes with thyroid levels
Nathan Goodyear

Breast Cancer Research | Full text | Circulating serum xenoestrogens and mammographic b... - 0 views

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    study finds increased BPA and phthalates in women is associated with increased breast density.
Nathan Goodyear

Reproductive and developmental effects of p... [Crit Rev Toxicol. 2014] - PubMed - NCBI - 0 views

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    phthalates are xenoestrogens that is toxic to male reproductive health.
Nathan Goodyear

Prenatal Exposure to Phthalates is Associated with Reduced Masculine Behavior in Boys - 0 views

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    phthalate exposure associated with reduced masculinity of boys
Nathan Goodyear

Environmental anti-androgens and male reproductive health: focus on phthalates and test... - 0 views

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    good review of the effect of environmental xenoestrogens and low T in men.
Nathan Goodyear

Ibuprofen alters human testicular physiology to produce a state of compensated hypogona... - 0 views

  • The levels of LH in the ibuprofen group had increased by 23% after 14 d of administration
  • This increase was even more pronounced at 44 d, at 33%
  • We found an 18% decrease (P = 0.056) in the ibuprofen group compared with the placebo group after 14 d (Fig. 1A) and a 23% decrease (P = 0.02) after 44 d (Fig. 1C). Taken together, these in vivo data suggest that ibuprofen induced a state of compensated hypogonadism during the trial, which occurred as early as 14 d and was maintained until the end of the trial at 44 d
  • ...27 more annotations...
  • We first investigated testosterone production after 24 and 48 h of ibuprofen exposure to assess its effects on Leydig cell steroidogenesis. Inhibition of testosterone levels was significant and dose-dependent (β = −0.405, P = 0.01 at 24 h and β = −0.664, P < 0.0001 at 48 h) (Fig. 2A) and was augmented over time
  • The AMH data show that the hypogonadism affected not only Leydig cells but also Sertoli cells and also occurred as early as 14 d of administration
  • Sertoli cell activity showed that AMH levels decreased significantly with ibuprofen administration, by 9% (P = 0.02) after 14 d (Fig. 1B) and by 7% (P = 0.05) after 44 d compared with the placebo group
  • Examination of the effect of ibuprofen exposure on both the ∆4 and ∆5 steroid pathways (Fig. 2B) showed that it generally inhibited all steroids from pregnenolone down to testosterone and 17β-estradiol; the production of each steroid measured decreased at doses of 10−5–10−4 M. Under control conditions, production of androstenediol and dehydroepiandrosterone (DHEA) was below the limit of detection except in one experiment with DHEA
  • Measuring the mRNA expression of genes involved in steroidogenesis in vitro showed that ibuprofen had a profound inhibitory effect on the expression of these genes (Fig. 3 B–D), consistent with that seen above in our ex vivo organ model. Taken together, these data examining effects on the endocrine cells confirm that ibuprofen-induced changes in the transcriptional machinery were the likely reason for the inhibition of steroidogenesis.
  • Suppression of gene expression concerned the initial conversion of cholesterol to the final testosterone synthesis. Hence, expression of genes involved in cholesterol transport to the Leydig cell mitochondria was impaired
  • A previous study reported androsterone levels decreased by 63% among men receiving 400 mg of ibuprofen every 6 h for 4 wk
  • We next examined the gene expression involved in testicular steroidogenesis ex vivo and found that levels of expression of every gene that we studied except CYP19A1 decreased after exposure for 48 h compared with controls
  • the changes in gene expression indicate that the transcriptional machinery behind the endocrine action of Leydig cells was most likely impaired by ibuprofen exposure.
  • Together, these data show that ibuprofen also directly impairs Sertoli cell function ex vivo by inhibiting transcription
  • ibuprofen use in men led to (i) elevation of LH; (ii) a decreased testosterone/LH ratio and, to a lesser degree, a decreased inhibin B/FSH ratio; and (iii) a reduction in the levels of the Sertoli cell hormone AMH
  • The decrease in the free testosterone/LH ratio resulted primarily from the increased LH levels, revealing that testicular responsiveness to gonadotropins likely declined during the ibuprofen exposure. Our data from the ex vivo experiments support this notion, indicating that the observed elevation in LH resulted from ibuprofen’s direct antiandrogenic action
  • AMH levels were consistently suppressed by ibuprofen both in vivo and ex vivo, indicating that this hormone is uncoupled from gonadotropins in adult men. The ibuprofen suppression of AMH further demonstrated that the analgesic targeted not only the Leydig cells but also the Sertoli cells, a feature encountered not only in the human adult testis but also in the fetal testis
  • ibuprofen displayed broad transcription-repression abilities involving steroidogenesis, peptide hormones, and prostaglandin synthesis
  • a chemical compound, through its effects on the signaling compounds, can result in changes in the testis at gene level, resulting in perturbations at higher physiological levels in the adult human
  • The analgesics acetaminophen/paracetamol and ibuprofen have previously been shown to inhibit the postexercise response in muscles by repressing transcription
  • Previous ex vivo studies on adult testis have indeed pointed to an antiandrogenicity, only on Leydig cells, of phthalates (41), aspirin, indomethacin (42), and bisphenol A (BPA) and its analogs
  • ibuprofen’s effects were not restricted to Leydig and Sertoli cells, as data showed that the expression of genes in peritubular cells was also affected
  • short-term exposure
  • In the clinical setting, compromised Leydig cell function resulting in increased insensitivity to LH is defined as compensated hypogonadism (4), an entity associated with all-cause mortality
  • compensated hypogonadic men present with an increased likelihood of reproductive, cognitive, and physical symptoms
  • an inverse relationship was recently reported between endurance exercise training and male sexual libido
  • AMH concentrations are lower in seminal plasma from patients with azoospermia than from men with normal sperm levels
  • inhibin B is a key clinical marker of reproductive health (32). The function of AMH, also secreted by Sertoli cells, and its regulation through FSH remain unclear in men
  • the striking dual effect of ibuprofen observed here on both Leydig and Sertoli cells makes this NSAID the chemical compound, of all the chemical classes considered, with the broadest endocrine-disturbing properties identified so far in men.
  • after administration of 600 mg of ibuprofen to healthy volunteers
  • 14 d or at the last day of administration at 44 d
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    ibuprofen alters genetic expression that results in decreased Testosterone production.
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