Global DNA methylation changes in rock pigeon (Columba livia) as a sentinel species due to polycyclic aromatic hydrocarbons exposure in Tehran (Iran) as a megacity.

Global DNA methylation, as an epigenetic modifications, can be a promising genomic marker for monitoring the contaminants and predicting their adverse health effects. The study aims to assess the effects of 16 PAH concentration on the altered DNA methylation levels in the kidney and liver of rock pigeon (Columba livia), as a sentinel species, from Tehran megacity as well as 40 days benzo(a)pyrene in vitro exposure: (0.1, 2.5, 5, 7.5, and 10 mg kg-1 bw). Data indicated that the total LMW-PAH (low molecular weight PAHs) group (120.22, 121.34, 103.69, and 128.79 ng g-1 dw in liver, kidney, skin, and muscle, respectively) in the Tehran samples have higher levels than the other PAHs groups. In addition, the DNA methylation level had negative relation with the total amount of PAHs in liver and kidney. A comparatively higher global DNA hypomethylation (by 8.65% in liver and 3.76% in kidney) was observed in birds exposed to B(a)P. Our results lead us to suggest that DNA hypomethylation in liver and kidney associated with the B(a)P may be useful biomarker discovery (more than the amount of PAH concentration in different tissues of C. livia) in urban areas. In conclusion, based on the overall results assessed, DNA methylation changes in pigeon may show a new target pathway for evaluation of environmental health.

Salinity effects on osmoregulation and gill morphology in juvenile Persian sturgeon (Acipenser persicus).

The effect of abrupt and 5-day gradual salinity transfers from freshwater (FW) to 11 ‰ Caspian Sea brackish water (BW) was investigated in juvenile Persian sturgeon Acipenser persicus with three different weight groups: 1-2 g (1.62 ± 0.27 g), 2-3 g (2.55 ± 0.41 g) and 3-5 g (4.28 ± 0.76 g). Mortality rates, blood osmotic pressure, gill morphology and branchial Na+, K+-ATPase (NKA) activity were measured 4 and 10 days after abrupt transfer and 9 and 15 days after the initial gradual transfer (i.e. 4 and 10 days after reaching Caspian Sea salinity). Fish under 3 g could not survive increased salinity, and the blood osmotic pressure of the remaining surviving fish increased and remained elevated. However, heavier fish were able to survive and successfully acclimate, even to rapid salinity change with osmotic pressure reduced to Caspian Sea osmolality levels. At the gill level, the developmental increase in chloride cell volume and a higher NKA content most probably allow juveniles weighing more than 2 g to sharply increase NKA activity if the fish are transferred to BW. The rapid chloride cell proliferation occurring with increased salinity should strengthen this acclimation response. Therefore, a drastic physiological change occurs when fish weigh more than 2 g that allows migration to higher salinities. The triggering signal on chloride cells must be further investigated in order to optimize this functional step.

A histological and ultrastructural study of the skin of rainbow trout (Oncorhynchus mykiss) alevins exposed to different levels of ultraviolet B radiation.

The current study was conducted to evaluate the effects of UV-B radiation on survival rate and histopathological changes in the skin structure and ultrastructure in rainbow trout (Oncorhynchus mykiss) alevins. In laboratory dark conditions, newly hatched rainbow trout alevins were exposed to two different doses of UV-B radiation (high dose: HD: 94.83 µW cm(-2)) and (low dose: LD: 68.75 µW cm(-2)) for 9 days (time of exposure: 15 min per day), whereas specimens kept in darkness served as a control group. At the end of the experiment, alevins exposed to HD-UVB had the lowest survival rate (43.9 ± 0.9%), whereas fish exposed to LD-UVB showed intermediate values (73.6 ± 0.4%) with regard to the control group (91.2 ± 0.2%). Light microscopic and scanning electron microscopic studies revealed necrosis, sunburned cells, epidermis lifting of the epidermis, reduced number of mucous cells, degeneration of mucous cells and destruction of pavement cell microridges in both UV-B exposed groups. Hemorrhage and inflation in the meningeal layer of the brain were also observed in 17% and 42% of fish exposed to LD- and HD-UVB, respectively.

Histopathological effects of atrazine on gills of Caspian kutum Rutilus frisii kutum fingerlings.

The use of chemical pesticides has increased environmental pollution and affects fishes as non-target organisms. To investigate the toxic effects of the widely used herbicide atrazine on Caspian kutum Rutilus frisii kutum fingerlings, fish were exposed to a sublethal concentration of half LC50 for 96 h. The main alterations visible in the gill tissue were detachment of the epithelium of the lamellae, necrosis, lamellar fusion, hyperplasia, club shaped lamellae, collapse of the lamellae, shrinkage and curling of the lamellae, and ultrastructural alterations such as necrosis of the apical microridges of the pavement cells. Results also showed that the gill ionocytes were fewer in number and larger in size in the atrazine-exposed fish. Atrazine appears to be highly toxic to Caspian kutum fingerlings even at a sublethal concentration (12.47 mg l(-1)) and acute exposure. This toxicity could affect gill respiration and ion regulation function of fingerlings by damaging tissue, pavement cells, and ionocytes.

Occurrence and distribution of two phthalate esters in the sediments of the Anzali wetlands on the coast of the Caspian Sea (Iran).

This study provides the first data on distribution of phthalate Acid esters (PAEs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 43 stations. Two PAEs consist of di(2-ethylhexylphthalate) (DEHP) and di-n-butyl phthalate (DnBP) were detected and the total concentrations of these two pollutants ranged from 0.25 to 43.12, 0.12 to 19.02µgg(-1) dry weight, respectively. Among all the 43 samples analyzed, no sample was found to be free of DEHP and DBP, which indicates these two phthalate esters were ubiquitous in sediments. The concentrations in the near urban regions were higher than other regions because of higher discharge of PAEs from plastic materials in urbanized areas. Concentrations of PAEs were positively correlated with total organic carbon (TOC). Generally the median concentrations of DEHP and DnBP in the sediments were 15 and 14 times higher than the ERL. These results show that the Anzali wetland are highly polluted by major PAE congeners consist of DEHP and DnBP.

Concentration of cd, pb, hg, and se in different parts of human breast cancer tissues.

Breast cancer is the major cause of cancer morbidity and mortality between women in the world. Metals involved in environmental toxicology are closely related to tumor growth and cancer. On the other hand, some metals such as selenium have anticarcinogenic properties. The aim of this study is to determine the concentration of cadmium, lead, mercury, and selenium in separated parts of tegmen, tumor, tumor adiposity, and tegmen adiposity of 14 breast cancer tissues which have been analyzed by graphite furnace atomic absorption (AA-670) and ICP-OES (ULTIMA 2CE). Our results show that Se and Hg have maximum and minimum concentration, respectively. Statistical analysis reveals no significant differences between metal accumulations in different parts of cancer tissues (P > 0.05) and this observation might be due to the close relation of separated parts of fatty breast organ. Thus, we could conclude that a high level of these heavy metals is accumulated in Iranian cancerous breasts and their presence can be one of the reasons of cancer appearance.

Starvation and refeeding effects on pyloric caeca structure of Caspian salmon (Salmo trutta caspius, Kessler 1877) juvenile.

Effect of starvation and refeeding on the structure of pyloric caeca was studied in the juveniles of Caspian Sea salmon. Juveniles (average body weight 12±0.1g) were subjected to four levels of feeding: full-fed for 6 weeks (FFF), 3 weeks fed and 3 weeks following starvation (FS), 3 weeks starved and 3 weeks fed (SF), and full-starved (SSS) for 6 weeks. Light microscopic studies showed significant reduction (p<0.05) in the enterocytes height and number, villus length, epithelial area and pyloric caeca total area in starved groups as compared to control group. These reductions were more significant (p<0.05) in long term starved group (SSS) than short term starved group (FS). Additionally, refeeding increased pyloric caeca size and enterocyte's number in SF group whereas, the epithelial total area and villus length did not reach the same area and length as control group. Results indicated that in Caspian Sea salmon juveniles food deprivation and consuming of food source, adversely affected the tissue of pyloric caeca while refeeding can be effective on healing tissue damage.

Effects of salinity and ultraviolet radiation on the bioaccumulation of mycosporine-like amino acids in Artemia from Lake Urmia (Iran).

We investigated the effects of salinity and artificial UV radiation on the accumulation of mycosporine-like amino acids (MAAs) in sexual and parthenogenetic Artemia from Lake Urmia. The nauplii hatched from the cysts were cultured until adulthood under two salinities (150 and 250 g L(-1) ) and two light treatments (PAR and PAR+UVR) in the laboratory. Finally, the Artemia were analyzed for their concentration of MAAs. In most of the cases, the higher salinity level applied was found to increase the MAA concentrations in both Artemia populations significantly. The acquisition efficiency of MAAs in both Artemia populations increased under exposure to UVR-supplemented photosynthetically active radiation (PAR) compared to those raised under PAR, except for Porphyra-334. It was observed that combination of UV radiation and elevated salinity significantly increased the bioaccumulation of MAAs. Thus, the presence of these compounds in these populations of Artemia may increase their adaptability for living in high-UV and high-salinity conditions prevailing in Lake Urmia. Higher concentrations of MAAs in the parthenogenetic population of Artemia could be probably attributed to its mono sex nature and higher adaptation capacities to extreme environmental conditions.

Ionocyte Immunolocalization and the Effects of Ultraviolet Radiation on Their Abundance and Distribution in the Alenins of Caspian Sea Salmon, Salmo trutta caspius.

OBJECTIVE: On a global scale, stratospheric ozone depletion has caused an increase in UV-B radiation reaching the earth's surface. Ultraviolet radiation has long been suspected to be harmful to aquatic organisms. MATERIALS AND METHODS: In order to study ionocyte localization (by Na(+)/K(+)-ATPase immunolocalization) and the effects of UV radiation on the ionocytes of skin and gills, the alevins of Salmo trutta caspius were exposed to different doses of UV radiation [unit low doses (ULD) of: 60 µw/cm(2) UVC; 100 µw/cm(2) UVB and 40 µw/cm(2) UVA and unit high doses (UHD) of: 90 µw/cm(2) UVC; 130 µw/cm(2) UVB and 50 µw/cm(2) UVA] using two adjustable F8T5 UV-B, 302 nm lamps (Japan) for 15 minutes once a day in laboratory conditions. Alevins not subjected to UV exposure served as a control group. RESULTS: In both UV exposure groups, all the alevins died on the ninth day. No mortality was observed in the control group. The Na(+)/K(+)-ATPase immunolocalization study indicated that ionocytes were located, in lessening order, on the yolk sac, trunk, gills, opercula and rarely on the head skin. Immunohistochemical results showed significant reduction in the number of ionocytes on the yolk sac, with lesser reduction on the trunk in both UV exposure groups. In contrast, the number of immunofluorescence cells on the gill was significantly elevated. Our results also showed that the size of ionocytes was reduced on the trunk and yolk sac in the UV exposure groups, but not significantly. Deformation and destruction of ionocytes on the yolk sac and trunk were observed with scanning electron microscope (SEM) in the UV exposure groups. CONCLUSION: Our results showed that ionocytes were located mainly on the yolk sac, in lesser amounts on the trunk, gills and opercula, and rarely also on the head skin of alevins. UV radiation caused deformation and reduction in the number and size of ionocytes on the trunk and yolk sac. As the skin cells of trout alevins possess essential functions for respiration, osmoregulation, excretion and defense during this stage of life, the observed damage may have contributed to their suddenly mortality in the UV exposure condition.

Ultrastructural studies and Na+,K+-ATPase immunolocalization in the antennal urinary glands of the lobster Homarus gammarus (Crustacea, Decapoda).

Unlike in crustacean freshwater species, the structure and ultrastructure of the excretory antennal gland is poorly documented in marine species. The general organization and ultrastructure of the cells and the localization of Na(+),K(+)-ATPase were examined in the antennal gland of the adult lobster Homarus gammarus. Each gland is composed of a centrally located coelomosac surrounded ventrally by a labyrinth divided into two parts (I and II) and dorsally by a voluminous bladder. There is no differentiated nephridal tubule between them. The labyrinth and bladder cells have in common a number of ultrastructural cytological features, including basal membrane infoldings associated with mitochondria, apical microvilli, and cytoplasmic extrusions, and a cytoplasm packed with numerous vacuoles, vesicles, lysosome-like bodies, and swollen mitochondria. Each type of cell also presents distinctive characters. Na(+),K(+)-ATPase was detected through immunofluorescence in the basal part of the cells of the labyrinth and in the bladder cells with an increasing immunostaining from labyrinth I to the bladder. No immunoreactivity was detected in the coelomosac. The cells of the labyrinth and of the bladder present morphological and enzymatic features of ionocytes. The antennal glands of the lobster thus possess active ion exchanges capabilities.