engleski

Malondialdehyde concentrations in the intestine and gills of Vardar chub (Squalius vardarensis Karaman) as indicator of lipid peroxidation

Lipid peroxidation product, malondialdehyde (MDA), was studied in Vardar chub(Squalius vardarensis Karaman) as indicator of oxidative stress, using native fish from three rivers in northern Macedonia: mining impacted Zletovska and Kriva rivers, and agriculturally impacted Bregalnica River. MDA concentrations were measured in the intestine in spring and autumn of 2012, and in gills in autumn. The aims of the study were to establish the type of contamination which provokes more pronounced MDA increase, as well as the organ which more reliably reflects the occurrence of oxidative stress. MDA levels in the intestine in spring amounted to 3.29-155.8 nmol g-1, in autumn to 4.85-111.1 nmol g-1, whereas MDA concentrations in the gills in autumn were 7.69-147.5 nmol g-1. Stronger influence of organic contamination on development of oxidative stress was observed in both organs, as seen from higher median MDA concentrations in autumn in fish from highly pesticide contaminated Bregalnica River (gills: 78.4 nmol g-1 ; intestine: 23.5 nmol g-1) compared to highly metal contaminated Zletovska River (gills: 15.9 nmol g-1 ; intestine: 17.4 nmol g-1). The response of the gills to contamination was twice stronger than intestine. The majority of fish from pesticide polluted river had increased MDA in gills, in contrast to only sporadically increased MDA in the intestine. Our results indicated that development of oxidative stress strongly depends on the selected fish organ, and that gills seem to be a better choice for monitoring oxidative stress than intestine, due to their continuous and direct exposure to polluted river water.

gills ; intestine ; malondialdehyde ; metals ; pesticides ; Vardar chub

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