Immunotoxicity of the xenoestrogen 4-nonylphenol to the cockle Cerastoderma glaucum.
The in vivo effects of 4-nonylphenol (NP) on functional responses of haemocytes from the cockle Cerastoderma glaucum were investigated after 7 days exposure to sublethal NP concentrations (0, 0+acetone, 0.0125, 0.025, 0.05 and 0.1 mg/l NP). Haemocytes from both controls and exposed cockles were collected, and the effects of NP on total haemocyte count (THC) and volume of circulating cells, intracellular superoxide anion (O(2)(-)) levels, acid phosphatase and lysozyme-like activities in both haemocyte lysate (HL) and cell-free haemolymph (CFH) were evaluated. Exposure of cockles to 0.1mg/l NP significantly increased THC (p<0.05) with respect to controls. Analysis of haemocyte size frequency distribution showed that the haemocyte fraction of about 7-8 microm in diameter and 250 femtolitres in volume increased markedly in cockles exposed to the highest NP concentration tested. Apoptosis resulting in cell volume reduction in NP-exposed animals cannot be excluded. No statistically significant variation in intracellular O(2)(-) levels was observed. Conversely, significant increases (p<0.05) in acid phosphatase activity were observed in CFH from 0.05 and 0.1mg/l NP-exposed animals; no significant differences in enzyme activity were recorded in HL. Lysozyme-like activity also increased significantly in CFH from cockles exposed to 0.05 mg/l NP (p<0.05) and 0.1 mg/l NP (p<0.001). Instead, lysozyme-like activity decreased significantly (p<0.05) in the HL of animals exposed to 0.05 mg/lNP. Our results suggest that NP induces variations in the functional responses of haemocytes of C. glaucum, mainly by reducing cell membrane stability and promoting cell degranulation.
Matozzo
Valerio
V
Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. matozzo@civ.bio.unipd.it
Rova
Giulio
G
Ricciardi
Francesco
F
Marin
Maria Gabriella
MG
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D049873:Cardiidae / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology*; D002452:Cell Count; D006434:Hemocytes / Q000187:drug effects / Q000201:enzymology; D009113:Muramidase / Q000378:metabolism; D010636:Phenols / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D010636:Phenols; D014874:Water Pollutants, Chemical; D000135:Acid Phosphatase; D009113:Muramidase; C041594:4-nonylphenol