Zinc effect on the sea urchin Paracentrotus lividus immunological competence.
Pollution by heavy metals has become one of the most important problems in marine coastal areas as a consequence of anthropogenic inputs. Among metal contaminants, zinc, being considered not very toxic, is sometimes released into the sea in appreciable quantities and its concentration is loosely regulated. In this work we analyzed the effects of a high zinc concentration on the sea urchin Paracentrotus lividus immune system. In particular, after 24 h of zinc treatment, we evaluated coelomocytes morphology and composition as well as the zinc influence on some humoral parameters such as hemolysis, lysozyme-like activity and antibacterial activity on Vibrio alginolyticus. Our results evidenced that the presence of zinc affected both cellular and acellular components of the sea urchin immune system. The P. lividus coelomocytes changed in morphology and number; moreover, the amebocytes changed from a petaloid to a filipodial-like shape and the red spherula cells increased in number. Among the considered humoral effectors lysozyme-like activity and antibacterial activity on V. alginolyticus decreased in short-term to zinc treatment. The modifications in the sea urchin immunological competence might give an early indication of disease susceptibility thus suggesting to consider the examined defence mechanisms as potential biological indicators of metal pollution.
Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov. Lecce-Monteroni, 73100 Lecce, Italy. patrizia.pagliara@unisalento.it
Patrizia
P
Pagliara
Loredana
L
Stabili
D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004198:Disease Susceptibility / Q000276:immunology; D006461:Hemolysis / Q000187:drug effects; D007121:Immunocompetence / Q000187:drug effects*; D009113:Muramidase / Q000378:metabolism; D012617:Sea Urchins / Q000166:cytology / Q000187:drug effects* / Q000196:embryology / Q000276:immunology*; D013312:Stress, Physiological / Q000187:drug effects / Q000276:immunology; D044149:Vibrio alginolyticus / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; D009113:Muramidase; D015032:Zinc