Histopathological evaluation of the interrenal gland (adrenal homolog) of Japanese medaka (Oryzias latipes) exposed to graphene oxide

Abstract

Due to unique physicochemical properties and wide industrial and biomedical applications, graphene oxide (GO) is ubiquitous in the aquatic ecosystem. Using Japanese medaka (Oryzias latipes) fish as a model, we previously demonstrated minimal endocrine disrupting (ED) effects of GO on reproductive organs, and thyroids. Current study investigated the ED-effects of GO on the interrenal gland (IRG) of medaka.Breeding pairs of adult male and female fish were exposed to 0 mg/L (control) or 20 mg/L GO by continuous immersion for 96 h, or to 0 or 100 μg/g GO by intraperitoneal administration. Also, 1 day post-hatch (dph) larvae were exposed to different concentrations of GO (2.5-20 mg/L) for 96 h. IRG was evaluated by immunohistochemical techniques after 21 days depuration in adults and 6 weeks in larvae. IRG cells were counted and the nuclear area was measured in hematoxylin-eosin stained sections using ImageJ software. We found that IRG is distributed adjacent to the posterior cardinal vein and its branches within the head kidney. Columnar/oval shaped periodic acid-Schiff negative, tyrosine hydroxylase positive cells are arranged either in a single, or in groups, sometimes encircling a sinusoid, or in a straight chord, laying adjacent to the endothelium of the cardinal vein, and having eosinophilic cytoplasm with round/oval basophilic nuclei. GO effect on nuclei and cell population in IRG was inconsistent; depending on exposure route, sex, and/or age of the fish. Also, because of its high adsorptive property and sharp edges, GO probably agglomerated on IRG, and induced physical injury, and ED effects.

Per‐ and polyfluoroalkyl substances activate UPR pathway, induce steatosis and fibrosis in liver cells

“…Due to unique physicochemical properties and industrial applications graphene oxide (GO) is used as a filter material for removing perfluorinated substances and trihalomethanes from drinking water 70 . A recent study showed that in a fish model ( Oryzias latipes ), GO exposure affects endocrine disruption (ED), thyroids minimally, 71 and inter renal gland (IRG) of medaka inconsistently 72 . Further study indicates that the GO effect depends on exposure route, sex, and/or age of the fish and that probably increased agglomeration of IRG, physical injury, and ED.…”

Experimental data-sets on the histopathological and immunohistological assessment of the Interrenal gland (adrenal homolog) of Japanese medaka (Oryzias latipes) fish exposed to graphene oxide

“…The procedure of GO synthesis, dilution, sonication, application to the animal was described previously [1 , 2 , 8] . Briefly, the GO used in the experiment was either synthesized in the laboratory or obtained from a commercial source (Sigma-Aldrich, St. Louis, MO, USA).…”

“…The adult medaka fish we used for histological/histochemical/immunohistochemical evaluation of interrenal gland (adrenal homolog) were obtained from our previous GO experiments on Japanese medaka adults (IMR fish [8] , IP fish [1 , 2] ). We have used two methods of GO exposure (IMR and IP) for adult fish.…”

“…Briefly, before exposure to GO (either by IMR or IP), the fish were maintained as a breeding pair (one male and one female) in 500 mL BSS in 1L glass jar in the laboratory conditions (25±1 ˚C and 16h light: 8h dark Light cycle). When they breed successfully for one week (7 days), the fish were used for GO exposure either by IMR (20 mg/L) or by IP (100 µg/g) [1 , 2 , 8] . For IMR experiment (body weight of control male and female fish is 228.8±25.61 mg, n = 4 and 323.8±14.7 mg, n = 4, respectively; and GO-exposed fish, male 229±10.98 mg, n = 5; female fish 280.2±14.65 mg, n = 5) we have used only one concentration of GO (20 mg/L) for exposure (96h in GO with refreshing of media every 24 h and then depurated for 21 days in a GO-free environment) (please see the schematic diagram in Fig.…”

“…For identification of the IRG in medaka head kidney, we followed immunohistochemical detection of TH enzymes in the medaka kidney by a method described by Shin et al [11] with some modifications ( Fig. 2 g–j) [8] . In brief, tissue sections (5 µm thickness) on glass slides were deparaffinized in xylene rehydrated in graded alcohols and brought to tap water.…”