Pollutant-specific and general lysosomal responses in digestive cells of mussels exposed to model organic chemicals
Marigómez, I.; Baybay-Villacorta, L. (2003). Pollutant-specific and general lysosomal responses in digestive cells of mussels exposed to model organic chemicals. Aquat. Toxicol. 64(3): 235-257
In: Aquatic Toxicology. Elsevier Science: Tokyo; New York; London; Amsterdam. ISSN 0166-445X; e-ISSN 1879-1514, meer
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| Trefwoorden |
Anatomical structures > Digestive system
ANE, Biscay Bay
Biomarkers
Cell constituents > Cell organelles > Lysosomes
Eukaryotes > Animals > Invertebrates > Mollusca > Bivalvia > Shellfish > Mussels
Mussels
Organic chemicals
Organic chemicals
Organic matter
Mytilus galloprovincialis Lamarck, 1819 [WoRMS]
Bay of Biscay [Marine Regions]
Marien/Kust |
| Auteurs | | Top |
- Marigómez, I., correspondent
- Baybay-Villacorta, L.
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| Abstract |
The present study was carried out to elucidate whether lysosomal size reduction in digestive cells of mussels Mytilus galloprovincialis constitutes a selective response against a particular group of organic chemical compounds, in contrast to the lysosomal enlargement characteristic of general stress response. Mussels were treated with di(2-ethylhexyl) phthalate (DEHP), benzo(a)pyrene (B[a]P), and the water accommodated fraction (WAF) of a lubricant oil, which were daily applied by either injection through the adductor muscle for 7 days or water-exposure for 21 days. Control mussels were either kept untreated in clean sea water, or treated with acetone (injection and water-exposure), vehicle used for DEHP and B[a]P. A third set of controls consisted of mussels with pierced shell kept in clean seawater. Digestive glands were excised at various treatment days and β-glucuronidase activity was demonstrated in 8-μm cryotome sections. Lysosomal volume, surface and numerical densities, and surface-to-volume ratio were quantified by image analysis. Other sections were stained with oil red 0 to demonstrate neutral lipids and changes in lipid levels were quantified by image analysis. Neutral lipid accumulation in digestive cells was used as a complementary indication of exposure to organic chemicals. It resulted to be a very prompt and all-or-nothing response, which reached a plateau before 1 day of treatment with WAF, DEHP and B[a]P after both injection and water-exposure. DEHP-treatment induced a general stress response characterised by lysosomal enlargement in digestive cells, which was already induced after 1 day. Treatment with either WAF or B[a]P elicited a comparable biphasic response. A transient lysosomal enlargement, shorter with WAF than with B[a]P treatment, was evidenced after both injection and water-exposure. Further, under water-exposure conditions, WAF reduced the endo-lysosomal system in size more markedly than B[a]P. Such lysosomal size reduction constitutes a transient response after exposure to diverse organic xenobiotics (acetone, WAF and B[a]P). In addition, this lysosomal size reduction might be followed by a further lysosomal enlargement, which later might yet again give rise to an apparent lysosomal size reduction under chronic exposure conditions. As a whole, the lysosomal response is intricate and cannot be simply interpreted in environmental pollution monitoring programmes. Nevertheless, it still constitutes a powerful and sensitive biomarker extremely useful as early-warning signal. |
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