Güler Ünal

Effects of 17α-ethynylestradiol and nonylphenol on liver and gonadal apoptosis and histopathology in Chalcalburnus tarichi

Chalcalburnus tarichi is an endemic cyprinid fish living in the Lake Van basin located in the Eastern Turkey. Fish (3+ ages) were exposed to 17α‐ethynylestradiol (EE2; 1, 10, 100 ng L−1; nominal concentrations) and nonylphenol (NP; 10, 60, 200 μg L−1; nominal concentrations) for 32 days under semistatic daily renewal conditions. The exposure period was followed by an evaluation of liver and gonadal apoptosis and gonad histopathology in males and females. Exposure to the highest concentrations of EE2 (100 ng L−1) and NP (200 μg L−1) caused significant increases in the extent of apoptosis in liver and gonads. Treatment with 100 ng L−1 of EE2 and 200 μg L−1 NP increased the number of TUNEL positive hepatocytes significantly in both sexes compared to controls. The rates of apoptosis in testicular germ cells and ovarian follicular cells were significantly greater at the same concentrations. Exposure to EE2 (100 ng L−1) and NP (60 and 200 μg L−1) caused thickening of interstitial connective tissue (fibrosis) in the seminiferous tubule wall and testis‐ova formation in males. In females treated with 100 ng L−1 EE2, increased percentage of atretic ooctytes and fibrotic areas in the ovarian somatic stromal tissue were found in the ovaries. Increase in atresia, without a statistical significance, and fibrotic stromal tissue were also noted in 60 and 200 μg L−1 NP treatments. Results suggest that EE2‐ and NP‐dependent hepatotoxicity and gonadotoxicity are causally related to the increase in apoptosis in C. tarichi.

The effects of 17α-ethynylestradiol, 4-nonylphenol and phenol red on vitellogenin synthesis in juvenile Chalcalburnus tarichi primary hepatocyte culture

In this study, the effects of the endocrine-disrupting chemicals known as 17α-ethynylestradiol (EE2), 4-nonylphenol (NP) and phenol red on vitellogenin (Vtg) synthesis in juvenile Chalcalburnus tarichi primary hepatocyte culture were investigated depending on dose and time. Hepatocytes were isolated by collagenase perfusion method and the cells were kept alive in cell culture for more than 2 weeks without using serum. As a result, it was determined that EE2 increased the Vtg synthesis depending on dose and time (p < 0.05), while NP and phenol red did not have any effect on the Vtg synthesis in the Chalcalburnus tarichi primary hepatocyte culture. Besides that, it was observed that high doses of NP (10 -3 and 10-4M) had toxic effects to the hepatocyte culture, too.

A Trematode Parasite Infecting the Skin of Rana ridibunda Complex (Sensu Lato) from Daiaman (Muğla, Turkey)

ABSTRACT We examined the structure of the black spots on the ventral surface of Rana ridibunda specimens, which were collected from the west Anatolia region of Turkey, and a multi-cellular parasite was discovered under these spots on the dermis within a cyst. The number of melanocytes had increased and the connective tissue of the dermis had surrounded the cyst. The parasite was a trematode in its metacercarial stage.