Cytochemical responses of the lysosomal system and NADPH-ferrihemoprotein reductase in molluscan digestive cells to environmental and experimental exposure to xenobiotics

Abstract

Lysosomal characteristics and smooth endoplasmic reticulum (SER) associated NADPHfernhemoprotein (cytochrome P-450) reductase were measured cytochemically in the digestive cells of mussels A4ytilu.s edulis and periwinkles Littorina littorea exposed to environmental contaminants In Langesundfjord, Norway (PAHs, PCBs, metals) and to xenobiotics in an experimental facility (diesel oil and copper mixture). Lysosomal membrane stability was reduced in both mussels and periwinkles with increasing xenobiotic contamination In the field. Lysosomal and cytoplasmic unsaturated neutral lipid concentration was increased in contaminated mussels in the field, and lysosomal accumulation was associated with enlargement of secondary lysosomes; the latter was inversely correlated with lysosomal membrane stability. hpofuscin content and number of tertiary lysosomes increased in contaminated field mussels. These pathological changes are indicative of enhanced lysosomal autophagy and fatty degeneration. NADPH-ferrihemoprotein reductase activity was elevated in mussels from the 2 most heavily contaminated field sites. Activity of this enzyme was directly correlated with total PAHs. Lysosomal data from experimental exposures were less clear and difficult to interpret. Poor nutritional conditions possibly masked pollutant effects. However, mussels from the highest exposure concentration showed elevated lipofuscin. The observed sensitivity of the tests for lysosomal enlargement and lysosomal lipid, combined with their relative simplicity, indicate their potential for the detection of environmentally induced pathology, although better understanding of the mechanisms of toxicity would enhance theu utility.

Comparative Effects of Ingested PVC Micro Particles With and Without Adsorbed Benzo(a)pyrene vs. Spiked Sediments on the Cellular and Sub Cellular Processes of the Benthic Organism Hediste diversicolor

“…Cryosections were stained by the Schorml's reaction according to Moore (1988) and lipid peroxidation end-products quantified by image analysis (ImageJ 1.51 K, NiH, USA).…”

Assessment of Seasonal Variability of Cytochemical Responses to Contaminant Exposure in the Blue Mussel Mytilus edulis (Complex)

“…Laboratory studies confirm that lysosomal responses in the digestive cells show strong associations to contaminant exposure (Lowe et al 1981;Moore and Clark 1982;Moore et al 1985;Pipe and Moore 1986;Nott and Moore 1987;Axiak et al 1988;Moore 1988Moore , 1991Cajaraville et al 1989;Krishnakumar et al 1990;Winston et al 1991;Viarengo et al 1992). Parameters that were consistently indicative of contaminant exposure included lysosomal stability, nicotinamide adenine dinucleotide phosphate (NADPH)-ferrihemoprotein reductase activity, lipofuscin deposition, and accumulation of lysosomal and cytoplasmic unsaturated neutral lipid.…”

“…The slides were then analyzed using image analyses. Lysosomal stability, or labilization period (the time necessary to labilize the responsive fraction of lysosomal hydrolase in an acid buffer), was determined using the marker enzyme N-acetyl B-hexosaminidase (Bitensky et al 1973;Moore 1988). Multiple sections for each tissue sample were incubated at 37°C in a citrate buffer containing NaCl to labilize the lysosomal membrane.…”

“…This enzyme reaction product was stained using the methods of Van Noorden and Butcher (1986) and Moore (1988). Duplicate cryomold tissue sections were incubated in total darkness for 30 min at 37°C in a sealed, oxygen-free atmospheric nitrogen chamber.…”

Ca2+homeostasis and redox balance in Antarctic sea organisms: Effects of temperature and of environmental contaminants

“…= 534 nm). Lysosome alterations were also studied in digestive gland cells (Moore, 1988;Olsson et al, 1989;Winston et al, 1991), by using histochemical techniques as described in Abele et al (1998). In addition, to investigate the possibilities of the organism to counteract temperature-induced oxidative stress, we also assayed the activities of Superoxide dismutase (SOD) and catalase (CAT) in animals incubated at different temperatures, as described in Abele et al (1998).…”