M2 AM Aquatic Ecotoxicology (Part 1)
Monday, 14 November 2005: 8:00 AM - 11:40 AM in Ballroom 2

(KEY-1117-556325) Lethal and sublethal effects of simvastatin on two grass shrimp (Palaemonetes pugio) life stages.

Key, P¹, Hoguet, J¹, Reed, L¹, ¹ NOAA/NOS/NCCOS/CCEHBR, Charelston, SC

ABSTRACT- Urbanized estuarine watersheds may contain elevated contaminant levels in sediments and waters. Recently, concerns have emerged about the potential impacts associated with pharmaceutical products, which may enter estuaries by means of sewage treatment effluents, septic tank and landfill seepage, and agricultural run-off. This study investigated the effects of simvastatin, the active ingredient in Zocor, a highly prescribed lipid-regulating drug, on larval and adult grass shrimp, Palaemonetes pugio, an important estuarine species. Sublethal effects (changes in glutathione (GSH), lipid peroxidation (LPx), acetylcholinesterase and cholesterol levels) and lethal effects (survival) were determined. GSH, a ubiquitous tripeptide, has been shown to help maintain a normal immune system and reduce oxidative damage, while LPx, often caused by oxyradicals, can impart cellular damage. There were no significant differences in GSH levels in either larval or adult exposures, although GSH levels in larvae were significantly lower than in adults (p < 0.05). Lipid peroxidation levels were significantly higher than controls at 1.0 mg/L in both larvae and adults (p < 0.05). In addition, cholesterol and acetylcholinesterase levels in larvae and adults were also measured. Although adult survival was slightly affected (30% mortality at 10 mg/L), larvae were more susceptible with 100% mortality at 10 mg/L after 48 hours and an LC50 of 1.18 mg/L. Lower levels of GSH in larvae may have contributed to increased mortality associated with simvastatin exposure.

Key words: grass shrimp, simvastatin, biomarkers, larvae