Chlormequat chloride promotes rat embryonic growth and GH-IGF-1 axis

Influence of leptin administration to pregnant mice on fetal gene expression and adaptation to sweet and fatty food in adult offspring of different sexes

Elevated leptin in pregnant mice improves metabolism in offspring fed high-calorie diet and its influence may be sex-specific. Molecular mechanisms mediating leptin programming action are unknown. We aimed to investigate programming actions of maternal leptin on the signaling function of the placenta and fetal liver and on adaptation to high-calorie diet in male and female offspring. Female C57BL/6J mice received leptin injections in mid-pregnancy. Gene expression was assessed in placentas and in the fetal brain and liver at the end of pregnancy. Metabolic parameters and gene expression in the liver, brown fat and hypothalamus were assessed in adult male and female offspring that had consumed sweet and fatty diet (SFD: chow, lard, sweet biscuits) for 2 weeks. Females had lower blood levels of leptin, glucose, triglycerides and cholesterol than males. Consuming SFD, females had increased Ucp1 expression in brown fat, while males had accumulated fat, decreased blood triglycerides and liver Fasn expression. Leptin administration to mothers increased Igf1 and Dnmt3b expression in fetal liver, decreased post-weaning growth rate, and increased hypothalamic Crh expression in response to SFD in both sexes. Only in male offspring this administration decreased expression of Fasn and Gck in the mature liver, increased fat mass, blood levels of glucose, triglycerides and cholesterol and Dmnt3a expression in the fetal liver. The results suggest that the influence of maternal leptin on the expression of genes encoding growth factors and DNA methyltransferases in the fetal liver may mediate its programming effect on offspring metabolic phenotypes.

Reproductive and developmental toxicity of plant growth regulators in humans and animals

Plant growth regulators (PGRs) are currently one of the widely used pesticides, as being considered to have relatively low toxicity compared with other pesticides. However, widespread use may lead to overexposure from multiple sources. Exposure to PGRs is associated with different toxicity that affects many organs in our body, such as the toxicity to testis, ovaries, liver, kidneys and brain. In addition, some PGRs are considered potential endocrine disrupting chemicals. Evidence exists for development and reproductive toxicity associated with prenatal and postnatal exposure in both animals and humans. PGRs can affect the synthesis and secretion of sex hormones, destroy the structure and function of the reproductive system, and harm the growth and development of offspring, which may be related to germ cell cycle disorders, apoptosis and oxidative stress. This review summaries the reproductive and developmental toxicity data available about PGRs in mammals. In the future, conducting comprehensive epidemiological studies will be crucial for assessing the reproductive and developmental toxicity resulting from a mixture of various PGRs, with a particular emphasis on understanding the underlying molecular mechanisms.

Agrochemicals in freshwater systems and their potential as endocrine disrupting chemicals: A South African context

South Africa is the largest agrochemical user in sub-Saharan Africa, with over 3000 registered pesticide products. Although they reduce crop losses, these chemicals reach non-target aquatic environments via leaching, spray drift or run-off. In this review, attention is paid to legacy and current-use pesticides reported in literature for the freshwater environment of South Africa and to the extent these are linked to endocrine disruption. Although banned, residues of many legacy organochlorine pesticides (endosulfan and dichlorodiphenyltrichloroethane (DDT)) are still detected in South African watercourses and wildlife. Several current-use pesticides (triazine herbicides, glyphosate-based herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D) and chlorpyrifos) have also been reported. Agrochemicals can interfere with normal hormone function of non-target organism leading to various endocrine disrupting (ED) effects: intersex, reduced spermatogenesis, asymmetric urogenital papillae, testicular lesions and infertile eggs. Although studies investigating the occurrence of agrochemicals and/or ED effects in freshwater aquatic environments in South Africa have increased, few studies determined both the levels of agricultural pesticides present and associated ED effects. The majority of studies conducted are either laboratory-based employing in vitro or in vivo bioassays to determine ED effects of agrochemicals or studies that investigate environmental concentrations of pesticides. However, a combined approach of bioassays and chemical screening will provide a more comprehensive overview of agrochemical pollution of water systems in South Africa and the risks associated with long-term chronic exposure.