RESEARCH ARTICLE
Hematological and histopathological effects of silver nanoparticles
in rainbow trout (Oncorhynchus mykiss)—how about increase
of salinity?
Hamid Salari Joo
1
&
Mohammad Reza Kalbassi
1
&
Seyed Ali Johari
2
Received: 14 October 2017 / Accepted: 28 February 2018 / Published online: 22 March 2018
#
Springer-Verlag GmbH Germany, part of Springer Nature 2018
Abstract
Hematological and histopathological toxicities of silver nanoparticles (Ag-NPs) to rainbow trout were assessed in three water
salinities: 0.4 ppt (low salinity), 6 ± 0.3 ppt (moderate salinity), and 12 ± 0.2 ppt (high salinity). The concentrations of Ag-NPs in the
low salinity were 0.032, 0.1, 0.32, and 1 ppm, and in the moderate and high salinities were 3.2, 10, 32, and 100 ppm. The results
indicated a concentration-dependently increased (thrombocyte, monocyte, and large lymphocyte) and decreased (neutrophil and
small lymphocyte) white blood cell count in the Ag-NP treatments in the low salinity than the other ones in the moderate and high
salinities. Red blood cell volume significantly increased in all of the experimental groups exposed to higher Ag-NP concentrations,
especially those in the low salinity. In the moderate and high salinities, blood plasma total protein decreased in 10 and 32 ppm Ag-
NP treatments, but albumin increased in the groups in the low salinity. Blood plasma ions (Cl
−
,Na
+
,K
+
,Ca
2+
,andMg
2+
) showed
high changes in the higher Ag-NP treatments. In all treatments, gill histological analysis demonstrated a time- and Ag-NP
concentration-dependent extent of abnormalities, with the highest epithelial lifting in 1 ppm Ag-NPs in the low salinity and also
the highest necrosis and aneurism in the 32 ppm treatments in other salinities. Lower Ag-NP concentrations in the low salinity led to
fibrosis, villus fusion, inflammation, vacuolization, and microvillus hyperplasia in the gut, yet villi lifting and necrosis in 0.32 and
1 ppm of Ag-NPs were the main anomalies. In addition to the mentioned alterations, villi abolitions predominantly occurred in
32 ppm Ag-NP concentrations in the moderate and high salinities. Overall, despite exposing to lower Ag-NP concentrations, the
fish kept in the low salinity demonstrated more vulnerability to Ag-NPs than those in the other salinities.
Keywords Blood cells
.
Plasma ions
.
Total protein
.
Albumin
.
Intestine
.
Gill
Introduction
Nanosilver is a new name with the prefix Bnano^ in the twenty-
first century, although silver particles with diameters lower than
10 nm were mentioned in 1889, when being used to prevent
bacterial growth (Massarsky et al. 2014b;Nowacketal.2011).
Over time, the emergence of antibiotics and unknown-remaining
mechanisms of silver toxicity gradually led to a decline in the
application of this substance (Choi et al. 2009). Recently, how-
ever, the background knowledge of silver antibacterial effects and
unsatisfactory performance of antibiotics on killing the strains of
infectious microorganisms have consequently lead to revert to the
utilization of silver, but in form of synthetically nano-sized parti-
cles (1–100 nm) (Emam and Ahmed 2016;Varneretal.2010).
Therefore, mainly due to their anti-microbial properties, silver
nanoparticles (Ag-NPs) are the fastest increasing manufactured
Responsible editor: Philippe Garrigues
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s11356-018-1663-5) contains supplementary
material, which is available to authorized users.
* Mohammad Reza Kalbassi
kalbassi_m@modares.ac.ir
Hamid Salari Joo
h.salary1365@gmail.com
Seyed Ali Johari
sajohari@gmail.com
1
Department of Marine Sciences, Tarbiat Modares University,
Mazandaran, Noor, Iran
2
Aquaculture Department, Natural Resources Faculty, University of
Kurdistan, Sanandaj, Iran
Environmental Science and Pollution Research (2018) 25:15449–15461
https://doi.org/10.1007/s11356-018-1663-5
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