Endocrine toxicants including 2,3,7,8-terachlorodibenzo-p-dioxin (TCDD) and dioxin-like chemicals and endometriosis: is there a link?

Endometriosis is a common gynecologic disease of unknown etiology affecting approximately 10-15% of women of reproductive age and 50% of infertile women. Estrogen dependence and immune modulation are established features of endometriosis but do not adequately explain the cause of this disorder. In recent years evidence indicated that exposure to environmental toxicants possessing estrogenic activity resulted in endometriosis.

Environmental contaminants and human infertility: hypothesis or cause for concern?

Throughout the 1980s and 1990s the crude human birth rate (live births per 1000 population) declined, indicating reduced fertility and suggesting a potential decline in fecundity (the potential to conceive). Detection of environmental contaminants in human tissues, together with reports of a global decline in semen quality, further fueled speculation that human infertility rates are increasing and environmental toxicants are potentially important causal agents associated with this change. However, there is little compelling evidence to suggest that infertility rates amongst the general population have changed over time.

Toward less confusing terminology in endocrine disruptor research.

The realization that environmental contaminants interact with hormone receptors and mimic or antagonize the actions of endogenous hormones led to introduction of terms such as endocrine disruptor, endocrine disrupter, hormonally active chemicals, and hormone mimics into the scientific and lay press. Reports suggesting a link between exposure to chemicals adversely affecting the endocrine system and (1) increasing rates of hormone-dependent cancers (breast, prostate, and testicular), (2) developmental detrimental effects in the male reproductive tract, (3) falling sperm counts, and (4) endometriosis resulted in an explosion of research, regulatory actions, and policy changes aimed at better understanding the hazards posed by these chemicals with subsequent restriction in their use. With increasing concern, there is worldwide action to develop testing strategies to allow for early identification of chemicals possessing endocrine disruptor activity.

Granulosa cell aromatase activity in women undergoing IVF: a comparison of good and poor responders.

Objective: We wished to investigate the aromatase activity (AA) of granulosa cells (GCs) in women undergoing ovarian follicular stimulation for in vitro fertilization (IVF).

Methods: Granulosa cells were harvested from follicular fluid aspirated at the time of oocyte retrieval in women undergoing IVF. Data related to the follicular stimulation and IVF were collected by chart review.

Quantification of benzo[a]pyrene and other PAHs in the serum and follicular fluid of smokers versus non-smokers.

Cigarette smoking is a well-established reproductive hazard that has been linked with decreased fertility in both smokers and those exposed to second hand smoke. The chemical components responsible for the reproductive toxic effects of cigarette smoke are unknown. Moreover, exposure of reproductive tissues to the chemical constituents of cigarette smoke is largely unknown.

Follicle growth is inhibited by benzo-[a]-pyrene, at concentrations representative of human exposure, in an isolated rat follicle culture assay.

Background: The adverse effects of cigarette smoking on human fertility have been well documented. However, the mechanism(s) underlying the detrimental effects of cigarette smoking are unknown. Using a novel isolated rat follicle culture assay, we tested the hypothesis that benzo-[a]-pyrene (B[a]P), a constituent of cigarette smoke, can inhibit follicle growth.