## 8 Translocation of Micro and Nanoplastics to Kidney  
As in other organs, micro and nanoplastics were found in fish kidney too [177]. They were found in kidney of 11 commercial fish species collected from the marine fish market [178], but also in fish exposed to them in laboratory [43]. On the other hand, [PERSON] and his team [179] did not detect microplastics in kidney fish after exposure in their laboratory. This inconsistency may be due to the different plastic sizes employed by [PERSON] [43] and [PERSON]'s teams [179]: respectively, 39.4 nm and 150-180 \(\upmu\)m (Table 3). The literature reports that after MPs and NPs exposure, a damage in kidney can occur and this can also involve the immunogenic part of this organ: the head kidney. For instance, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Specimens** & \begin{tabular}{c} **Micro- and** \\ **Nano-Plastics Sizes** \\ **and Type** \\ \end{tabular} & **Concentration** & \begin{tabular}{c} **Exposition** \\ **Time** \\ \end{tabular} & **Effects** & **References** \\ \hline \begin{tabular}{c} sheepshead \\ minnow \\ (_Cyrriondon_ \\ _variegatus_) larvae \\ \end{tabular} & 150–180 \(\upmu\)m PE & 50 and 250 mg/L & 4 days & - & No effects & [179] \\ \hline \begin{tabular}{c} Japanese medaka \\ (_Oryzias latipes_) \\ \end{tabular} & 10 \(\upmu\)m PS & 500, 1000 and 2000 \(\upmu\)g/g & 10 weeks & - & glomerulopathy & [180] \\ \hline \begin{tabular}{c} Japanese medaka \\ (_Oryzias latipes_) \\ \end{tabular} & 10-20 \(\upmu\)m sized PES & 10,000 Microplastic & 21 days & - & No alteration & [181] \\ \hline \begin{tabular}{c} Gilhead seabream \\ (_Sparus aurata_) \\ \end{tabular} & From 40 to 150 \(\upmu\)m & 100 mg/kg and 500 mg/kg & 15 and 30 days & - & alteration of \\ \begin{tabular}{c} (_Sparus aurata_) \\ \end{tabular} & From 40 to 150 \(\upmu\)m & 100 mg/kg and 500 mg/kg & 15 and 30 days & - & [182] \\ \hline \begin{tabular}{c} Zebrafish \\ (_Dunio rerio_) \\ \end{tabular} & \begin{tabular}{c} -70 \(\upmu\)m (mean) sized \\ PA, PE, PP, PVC \\ \end{tabular} & 0.001–10.0 mg/L & 10 days & - & No histological & [137] \\ \hline \begin{tabular}{c} Zebrafish Larvae \\ (_Danio rerio_) \\ \end{tabular} & Fluorescent PSNPs & & & & \\ \
\begin{tabular}{c} Zebrafish Larvae \\ (_Danio rerio_) \\ \end{tabular} & internally dyed with & 0.2, 2, and 20 mg/L & 120 hpf & - & transcriptional & [115] \\
\begin{tabular}{c} Fluorescent Green \\ (468/508 nm) \\ \end{tabular} & & & & & \\ \hline \hline \end{tabular} Table abbreviations. PVC-MPs: polyvinylchloride microparticles, polystyrene (PS), polyester (PES), polypropylene (PP), polyramides (PA), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene nanoplastic (PSNPs).  
\end{table} 
Table 3: Micro and nanoplastics effect on kidney fish. [PERSON] et al. [183] found, through the histological analysis, alterations in kidney after MPs exposure, like glomerulopathy and nephrogenesis. Glomerulopathy was showed as expansion and congestion of glomerular capillaries, with severe cases with increased glomerular size (i.e., glomerulomegaly) and expansion of Bowman's space while nephrogenesis was evident as tubular and/or glomerular generation or regeneration. The authors found that glomerulopathy and nephrogenesis, in exposed fish, increases in severity with exposure level. Kidney health status can be also evaluated by assessing creatinine and uric acid that can be considered as an index of the glomerular filtration rate and as a biomarker for kidney dysfunction. So, [PERSON] et al. [184], after 15 days exposure to MPs, detected a significant increase of fish kidney function (creatinine and uric acid). MPs-dependent kidney damage was also demonstrated by [PERSON] et al. [182], testing creatine kinase, albumin, and globulin in fish. These parameters were significantly increased in serum from fish fed with PVC-MPs at 100 mg/kg for 15 days and 30 days. Alterations in plasma globulin and albumin were also obtained on juvenile _C. gariepinus_ by [PERSON] et al.