Laura Martínez-Tabche

Toxic effect of sodium dodecylbenzenesulfonate lead, petroleum, and their mixtures on the activity of Acetylcholinesterase of Moina macrocopa In vitro

The inhibition of acetylcholinesterase activity (AChE) in Moina macrocopa homogenized with sodium dodecylbenzenesulfonate (DBSS), lead (Pb), crude oil (PO), and their mixtures was investigated. When the homogenized cladoceran were exposed to these compounds in vitro, AChE activity revealed that PO was the most potent anticholinesterase agent, followed by Mixture IV (DBSS-PO), Mixture I (DBSS), Mixture III (PO-DBSS), Pb, DBSS, and Mixture II (Pb-DBSS). All compounds and their mixtures caused inhibition of M. macrocopa homogenized cholinesterase. This bioassay technique seems to have considerable potential as a rapid, sensitive, and inexpensive procedure for hazard assessment and environmental evaluation. ©1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 211–215, 1997

TOXIC EFFECTS OF ZINC FROM TROUT FARM SEDIMENTS ON ATP, PROTEIN, AND HEMOGLOBIN CONCENTRATIONS OF LIMNODRILUS HOFFMEISTERI

Zinc (Zn) is a nutritionally essential metal, and deficiency results in severe health consequences to aquatic organisms. In this study toxicity data for Limnodrilus hoffmeisteri produced by Zn in systems using three natural sediments (trout farms: El Oyamel, El Truchón, and El Potrero) are presented. Hemoglobin, adenosine triphosphate (ATP), and protein concentrations were measured in L. hoffmeisteri exposed to spiked sediments, as indicators of exposure. Physicochemical characteristics of water and sediments were also considered. Zn concentrations were measured in water and sediment. El Oyamel, El Truchón, and El Potrero pond sediments did not have similar physicochemical characteristics. Zn concentrations of water obtained from the rustic ponds were near 0.4575 mg/L; however, this metal was always found to be higher in the sediments (0.0271-0.9754 mg/kg). The bioassay with worms demonstrated that pond sediments from El Oyamel, El Potrero, and El Truchón produced toxicity since ATP and protein concentrations were low compared to controls (organisms without metal). All spiked sediments had a significant reduction effect on ATP, protein, and hemoglobin concentrations. This investigation clearly shows that sediments of El Truchón, El Oyamel, and El Potrero possess toxicity potential. These results suggest the usefulness of these bioassays to evaluate the toxicity of sediments polluted with heavy metals.Zinc (Zn) is a nutritionally essential metal, and deficiency results in severe health consequences to aquatic organisms. In this study toxicity data for Limnodrilus hoffmeisteri produced by Zn in systems using three natural sediments (trout farms: El Oyamel, El Truchon, and El Potrero) are presented. Hemoglobin, adenosine triphosphate (ATP), and protein concentrations were measured in L. hoffmeisteri exposed to spiked sediments, as indicators of exposure. Physicochemical characteristics of water and sediments were also considered. Zn concentrations were measured in water and sediment. El Oyamel, El Truchon, and El Potrero pond sediments did not have similar physicochemical characteristics. Zn concentrations of water obtained from the rustic ponds were near 0.4575 mg/ L; however, this metal was always found to be higher in the sediments (0.0271-0.9754 mg/kg). The bioassay with worms demonstrated that pond sediments from El Oyamel, El Potrero, and El Truchon produced toxicity since ATP and protein concentrations were low compared to controls (organisms without metal). All spiked sediments had a significant reduction effect on ATP, protein, and hemoglobin concentrations. This investigation clearly shows that sediments of El Truchon, El Oyamel, and El Potrero possess toxicity potential. These results suggest the usefulness of these bioassays to evaluate the toxicity of sediments polluted with heavy metals.

Acetylcholinesterase activity of the freshwater cladoceran, Moina macrocopa, used as an in vitro screening tool for water quality

A rapid, inexpensive enzymatic method is proposed for screening water quality in the laboratory, on board ship or on-site. The method uses the enzyme acetylcholinesterase extracted with Triton X-100 from the supernatant of a homogenate of the cladoceran, Moina macrocapa. Modification of the specific activity of the enzyme compared to controls is measured during incubation of the enzyme extract with water from various sources. This study demonstrated differential response to enzyme activity in water from a large reservoir (Ignacio Ramirez) compared with effluent from an oil refinery (18 de Marzo). In vitro AChE activity is suggested as a rapid test to identify water samples that are toxic or of poor quality and that should be subject to further chemical analysis and toxicity testing.

Toxicity and Uptake of Zinc in the Planarian Dugesia dorotocephala in Natural Sediments

ABSTRACT Zinc uptake and protein, hemocianine, and metallothionein concentrations were studied in Dugesia dorotocephala exposed to Zn-spiked natural sediments in a recirculation system. Exposures to Zn ranged from 0.129 to 4.43 mg Zn/kg of sediment. Metallothionein and protein concentrations increased after treatment with Zn; however, the hemocianine concentration decreased. Metallothionein production could be an effective defense mechanism in planaria. The 96-h EC50 for Zn against D. dorotocephala was 12.52 mg Zn/kg of sediment.