Polybrominated diphenyl ethers and sperm quality.

BACKGROUND: Polybrominated diphenyl ethers are known to be endocrine disruptors and may affect male reproduction. This exploratory study investigated semen parameters and serum thyroid hormones in relation to serum PBDE, PCBs and p-p' DDE in adult men. METHODS: Fifty-two men were recruited in a fertility clinic. Semen counts were done for each participant. Serum thyroid hormone and PBDE, PCB and p-p' DDE levels were measured. Sociodemographic questionnaire were administered to each participant and all medical data were obtained from medical record. RESULTS: Semen mobility was negatively related to BDE-47, BDE-100 and ΣBDE. No relations were observed with other semen parameters. Thyroxin levels were negatively associated to serum BDE-47, BDE-99, ΣBDE and p-p' DDE and positively related to ΣPCB. No relations were observed between T3, TSH and any of the chemicals measured. CONCLUSION: These findings increased the evidence that PBDE may interfere with semen quality and thyroid status in general population.

Alteration of calcium homeostasis in primary preeclamptic syncytiotrophoblasts: effect on calcium exchange in placenta.

Preeclampsia (PE) is characterized by maternal hypertension, proteinuria, oedema and, in 30% of cases, by intrauterine growth retardation. Causes are still unknown; however, epidemiological and clinical studies have suggested alterations in maternal calcium metabolism. We suggested that in PE, calcium transport by the syncytiotrophoblast (ST) is disturbed. From total placental tissues, we studied the expression of: calcium channels (TRPV5, TRPV6 [transient receptor potential vanilloid]), calcium binding proteins (CaBP-9K, CaBP-28K), plasma membrane calcium ATPase (PMCA)1,2,3,4 pumps, ATP synthase, genes implicated in Ca(2+) release [inositol-1,4,5-triphosphate receptor (IP3R)1,2,3; Ryanodine receptor (RyR)1,2,3] and replenishment (SERCA1,2,3 [sarcoendoplasmic reticulum Ca(2+) ATPases]) from endoplasmic reticulum, channels implicated in mitochondrial Ca(2+) accumulation (VDAC1,2,3 [voltage-dependent anion channels]) and a marker of oxidative stress (hOGG1 [Human 8-oxoguanine-DNA glycosylase 1]), as well as the influence of these variations on calcium transport in primary ST cultures. The mRNA and protein levels were thereby examined by real-time PCR and Western blot analysis, respectively, in two different groups of pregnant women with similar gestational age: a normal group (n= 16) and a PE group (n= 8), diagnosed by a clinician. Our study showed a significant decrease in calcium transport by the ST cultured from preeclamptic placentas. We found a significant (P < 0.05) decrease in mRNA levels of TRPV5, TRPV6, CaBP-9K, CaBP-28K, PMCA1, PMCA4, ATP synthase, IP3R1, IP3R2, RyR1, RyR2 and RyR3 in PE group compared to normal one. We also noted a significant decrease in protein levels of TRPV5, TRPV6, CaBP-9K, CaBP-28K and PMCA1/4 in PE group. In contrast, SERCA1, SERCA2, SERCA3, VDAC3 and hOGG1 mRNA expressions were significantly increased in PE placentas. Calcium homeostasis and transport through placenta is compromised in preeclamptic pregnancies and it appears to be affected by a lack of ATP and an excess of oxidative stress.

Very low level environmental exposure to lead and prolactin levels during pregnancy.

Lead (Pb) is a well-known poison interfering with calcium homeostasis and dopaminergic pathway. We hypothesized that environmental Pb exposure can interact with prolactin (PRL) secretion, regulated by calcium and dopamine, during pregnancy and in fetus. The objective of this longitudinal study was to determine the relationships between blood Pb concentration and serum PRL levels in 101 pregnant women recruited during pregnancy and their fetuses exposed to low environmental levels of Pb. We observed a significant negative relationship between maternal blood Pb concentrations and maternal serum PRL levels. Cord blood PRL was weakly correlated with blood Pb levels. Our results suggest that maternal physiological parameters in pregnancy can be modulated by low level of Pb exposure and indicate a particular susceptibility of pregnant women to its toxic effects.

Blood manganese content at birth and cord serum prolactin levels.

Manganese (Mn) is both an essential element and, at a high dose, a potent neurotoxin that can interact with dopaminergic neurotransmission. Plasma prolactin (PRL), an indirect indicator of dopaminergic functioning, has been shown to vary with Mn exposure in adults, but little is known about this relation in the developing brain. The objective of this study was to examine the relations between maternal and cord Mn blood concentrations at birth and PRL cord blood levels. Blood Mn levels were determined in 87 pregnant women at delivery, and PRL was measured in the cord blood plasma. Mn cord blood concentration (mean 34.4 microg/l, range 16.7-89.4) was significantly and positively related to cord PRL levels. These findings suggest that Mn accumulation in utero could contribute to PRL level variation in neonates, which, in turn, may influence important developmental parameters.

[Biological materials collection within population of pregnant women at delivery]. / Recueil de tissus biologiques au sein d'une population de femmes parturientes.

Little is known about biochemical mechanisms associated with the normal psychomotor development of children. Many factors of the fetal environment likely interfere with these mechanisms. A prospective cohort study is essential to explain the implications of certain disturbances of biochemical nature during gestation on the later development of the nervous system. The study that we undertook with the maternity hospital Robert Debré had several objectives. The first was to examine, on an epidemiological scale, the possible role of the monoaminergic systems and the ATPases activity during the perinatal period on the later cognitive development of the child. The second was to study the influence of environmental in utero exposure on these mechanisms and consequently on the later psychomotor performances of the child. We examine here the advantages and the specific difficulties in such an approach within a population of women in childbirth.

Evolution of blood lead levels in urban French population (1979-1995).

BACKGROUND: The aim of the Council Directive of 29 March 1977 of the European Union was to measure non-occupational lead exposure levels in the general adult populations of European countries through biological monitoring. In France, such measurements were carried out during 1979 and 1982 in eight metropolitan areas (having more than 500 000 inhabitants), a period during which the lead content of petrol was decreased. The aim of this study conduct in 1995 was to evaluate the exposure trend to lead. METHODS: In 1995 this measurement was repeated, only in the three largest urban areas (Paris, Marseilles and Lyons). The same sampling method used in the first two campaigns was retained to ensure that the results of 1995 could be compared with those from 1979 and 1982. RESULTS: In these three metropolitan areas, the average blood lead levels decreased by the order of 60 microg/l between the beginning of the 1980's and 1995. This represents a fall of more than 50%. CONCLUSIONS: Certainly car pollution is not the only vector of dissemination of lead in the centre of urban zones, but it is there that the most sustained efforts at eradication have been made. The improvement we have observed is probably due to the policy of eliminating lead from petrol. In conclusion, the blood lead levels in French urban populations seem to have greatly decreased from those of the early 1980s.