endocrine disruption

Overweight and obesity are defined as a disease in which abnormal excessive body fat accumulation causes adverse effects on health, leading to a higher morbidity and mortality.

In this project we’ll try to examine if endocrine disrupting compounds (EDCs) are capable off disrupting pancreas, liver and adipocyt function, if they can cause changes in insulin, glucagon and leptin levels and if they can induce molecular mechanisms that could be associated with certain metabolic diseases such as diabetes, obesity and/or cardiovascular diseases. A limited list of endocrine disrupting chemicals, known as pollutants, will be studied. This project attempts to show that these chemicals disturb energy reservoirs of cells, specifically by intervening with glucose and/or lipid metabolism. Special attention will be directed to the elucidation of the mechanisms of action that underlie these disruption.

Over the last decade, increasing concern has been raised towards the potential of a diversity of environmental compounds to interfere with the endocrine system of humans and wildlife. Given the ubiquitous presence of these ‘endocrine disrupting chemicals’ (EDCs) in the aquatic environment – often at high concentrations – fish are inevitably exposed, resulting in a variety of adverse biochemical, physiological and reproductive effects, as demonstrated by researchers worldwide.

Until recently, most studies on endocrine disruption have focused on effects at the physiological level. In this research, we will evaluate the effects of endocrine disruption on a lower (gene expression) and a higher (reproductive behaviour) level of biological organization. Adult zebrafish are exposed to (potential) endocrine disruptors under flow-through conditions. After 4 and 28 days, fish are dissected and gonads are collected for the production of oligonucleotide microarrays. Gonadosomatic index (GSI) and vitellogenin of whole body homogenates are determined after 28 days. During every day of the first and the last week of exposure, fecundity and fertility are evaluated. Hatching is followed up until 4 days post-hatch. On day 4, 14 and 28, reproductive behaviour of 10 zebrafish (5 males and 5 females) in the control and high dose group is recorded at 3 time points, using a 3D-behaviour analysis system. Swimming velocity, swimming height and inter-individual interactions are calculated.

The genetic population structure of natural populations of the indirect developing (i.e. planctonic development) periwinkle, Littorina littorea and of the direct developer (i.e. non-planctonic development) L.