Repro endocrine disruptors

Cholesterol

Precursor for all steroid hormones

Steroids

• Secreted by ovary/testis

• Differ in structure but elicit different actions on tissues

Xenoestrogens

• synthetic hormones originating from outside of body

• Man made industrial chemicals from manufacturing industries

Persistent organic pollutants (POPs)

Highly lipophilic chemicals not easily biodegradable- accumulate in environment

non persistent edcs

Have low lipid solubility resulting In relatively short half life in humans & animals

Endocrine disrupting chemicals

• Structurally similar to steroid hormones & mimic/disrupt endogenous hormone action

• Often elicit estrogenic effects

• Lipophilic but does not get degraded within body & then bio accumulate in fat tissue/food chain

  ex. PCBs, atrazine

Steroid hormone receptors

Not highly specific & accept more than one type of ligand molecule

Common EDCs

• Bisphenol A & Phthalates

• Triclosan

• Dioxins

• Perchlorate

• PFAS

• PBDE

• PCB

• Medication & cosmetic

• Phytoestrogens

P,P DDE

Most prevalent metabolite of pesticide DDT

Beta HCH

Isomere of the pesticide lindane

PCB 153

One of 6 most abundant congeners of polychlorinated biphenyls in environment

Coumestrol

Phytoestrogen

17beta estradiol

Natural hormone & endogenous ligand of estrogen receptor

EDCs effect on folliculogenesis

• exposure of primordial follicles to ___ can lead to permanent or early infertility

• Graafian follicle can result in altered hormone levels of infertility

EDCs effect on steroidogenesis

• can alter expression, protein levels, or enzyme activity of steroidogenic enzymes, resulting in altered sex steroid hormones in females

EDCs can interfere with various human sperm functions & might impair fertilization

• EDCs directly activate CatSper Ca2+ channels on human sperm & evoke increase or decrease in [Ca2+] = leads to altered hyperactivation & acrosomal reaction

• Desensitize human sperm for progesterone & prostaglandins

EDCs mimic hormone E2

Can lead to E2 dominance & may increase risk of development of endometriosis

Endometrial ablation

Used to treat menorrhagia, endometrium surgically destroyed

Amenorrhea

Absence of menstruation

Oligomenorrhea

Skipping cycles

Endometrial polyps

Mushroom like growths that extend into uterine cavity

Hyperplasia

Excessive proliferation of endometrial cells/endometrium, may be caused by chronic endometrial E2 exposure without menstruation

Uterine fibroids

• aka leiomyomas or myomas

• Non cancerous rumours of uterine smooth muscle cell within myometrium layer