The sheepshead minnow Cyprinodon variegatus as a marine vertebrate model for investigating endocrine disrupting effects of triclosan

Poster (2012)

Zebrafish (Danio rerio) has been a prominent model in toxicology. This freshwater species present many advantages both in identifying endpoints of toxicity and in elucidating mechanisms of toxicity ... [more ▼]

Zebrafish (Danio rerio) has been a prominent model in toxicology. This freshwater species present many advantages both in identifying endpoints of toxicity and in elucidating mechanisms of toxicity. However, marine toxicologists lack such omnipotent model displaying similar advantages to zebrafish: small size, rapid breeding, and easy maintenance. We propose here the use of the sheepshead minnow Cyprinodon variegatus to define thyroid-disrupting effects of triclosan during pre-hatching development. Three females and two males were placed in each of the three breeding chambers designed for this experiment. More than 300 eggs were collected over three days and maintained in seawater with triclosan concentrations at 0, 100 ng.L-1, and 100 µg.L-1. Exposure of larvae to triclosan lasted until hatching. After hatching (six days post-spawning), 5 larvae per condition were placed in Bouin’s fixative for brain and thyroid histology. Length and body mass were measured. The body was frozen at -80oC to determine muscle thyroid hormone levels (T3 and T4), using radio-immunoassay techniques. Hatching success, in vivo observations, gross observation, thyroid hormone levels, histology will be determined and discussed in the framework of whether or not triclosan may alter thyroid metabolism during pre-hatching period of the sheepshead minnow. [less ▲]

STRATEGY FOR ASSESSING IMPACTS OF THYROID DISRUPTING CHEMICALS IN TELEOSTEANS

in Organohalogen Compounds (2011)

Acetylcholinesterase activity as a biomarker of exposure to antibiotics and pesticides in the black tiger shrimp (Penaeus monodon).

in Ecotoxicology & Environmental Safety (2009), 72(5), 1463-70

This study aimed to assess the potentiality to use cholinesterase activity (ChE) in black tiger shrimp (Penaeus monodon) as a biomarker of exposure to 2 antibiotics (enrofloxacin, furazolidone) and 2 ... [more ▼]

This study aimed to assess the potentiality to use cholinesterase activity (ChE) in black tiger shrimp (Penaeus monodon) as a biomarker of exposure to 2 antibiotics (enrofloxacin, furazolidone) and 2 pesticides (endosulfan, deltamethrin), commonly used in Vietnamese farms. ChE from muscle and gills was first characterised using three different substrates and specific inhibitors. Results showed that both tissues possess only one ChE which displays the typical properties of an acetylcholinesterase (AChE). In a second part, shrimp (average weight of 8.8-10 g) were fed with medicated-feed containing 4g enrofloxacin (quinolone) or furazolidone (nitrofuran)/kg for 7 days, or exposed to 3 actual concentrations of endosulfan (0, 0.009, 0.09, 0.9 microg/L) or deltamethrin (0, 0.0007, 0.007, 0.07 microg/L) for 4 days. After treatment, animals were decontaminated during 7 days. We observed that AChE activity in muscle was not significantly affected in shrimp fed with enrofloxacin or furazolidone, while it significantly decreased (up to 28%) in gills of shrimp fed with furazolidone. Following endosulfan and deltamethrin exposure, no significant changes in AChE activity were observed in gills. However, a significant decrease occurred in muscle after 4 days exposure (inhibition of 30% and 49% at 0.9 microg/L endosulfan and 0.07 microg/L deltamethrin, respectively). While muscle AChE activity should be assessed to point out endosulfan or deltamethrin exposure, gill AChE activity impairment could indicate an exposure to furazolidone. The present study underlines the benefits to use AChE as a biomarker of chemotherapeutics as part of an integrated aquaculture management to reach industry sustainability. [less ▲]

Improvement of shrimp production sustainability and safety in Vietnam

Poster (2005)