Endokrin Bozucu Bileşiklerden Tetrabromobisfenol A'nın Gebe Sıçanlara Etkisinin Araştırılması
Özet
TBBP-A (tetrabromobisphenol-A), which is the most produced among the fire retardants, is found in high concentrations in textiles, plastic polymers, electrical equipment and industrial products. It is known to be endocrine disruptor and its use in canned interior coatings increases exposure in daily life, especially through diet. This situation is considered to be more risky for pregnant women. For this reason, in our study, it was aimed to investigate the effects of pregnant women on placental tissue after oral exposure to TBBP-A.
The three-week gestation period in rats is grouped into three trimesters (1 week each), and they correspond to three trimesters in humans. In our study, in line with this information, an experimental setup was created to examine the three trimesters, and the examination of the placental tissue that develops with pregnancy was based on.
In our study, 72 pregnant Rattus norvegicus rats were used. Each female, which was mated with male rats provided as breeding and sperm was detected in the female smear samples, was considered pregnant and included in the experimental groups. Experimental groups: GD10 (10th gestational day) control (corn oil), 20mg/kg (minimum), 200mg/kg (moderate), 400mg/kg (high) dose; GD15 (day 15 of gestation) control, 20mg/kg, 200mg/kg, 400mg/kg dose; GD20 (20th gestational day) is in the form of control, 20mg/kg, 200mg/kg, 400mg/kg. Each group was exposed to TBBP-A dissolved in corn oil by oral gavage method during the gestational day (days 10, 15 and 20). There are 6 rats in each group. During the application, the feed-water consumption and weight changes of the rats were recorded. After the last stage of sacrification, the tissues of the placenta, kidney, liver and ovary were taken, their weights were recorded, and the tissue was followed up to be examined histopathologically under the light microscope. All tissues were stained with H&E and placenta tissue was additionally stained with PAS staining method. Follicle Stimulating Hormone (FSH), progesterone, Luteinizing Hormone (LH), estrogen hormone analyzes were made from the serum obtained from the blood obtained from the hearts of rats. Estrogen from the ovarian homogenate of GD20 group fetuses and testosterone from the testicular homogenate of male fetuses were examined.
At the end of the experiment, it was determined that the food and water consumption and the ending weights of the GD20 group rats decreased. In the tissue weight findings, it was observed that the kidney and placenta relative weight values of the GD20 group rats decreased. It was determined that placental weight, embryo weight, placental X-axis length of GD15 group rats and embryo length and umbilical cord length of GD20 group rats were decreased. There was an increase in left kidney weight and placental index values of GD15 group rats.
Among the tissues examined histopathologically, congestion and sinusoidal enlargement in the liver tissue; Congestion in kidney tissue, glomerular atrophy, opening of glomerulus parietal leaves, tubular degeneration were observed. In placental tissue, congestion in all dose groups of GD10 200mg/kg, GD10 400mg/kg, GD15 and GD20 groups; In all dose groups of GD15 and GD20 groups, labyrinth region degeneration, cytoplasmic melting and pycnosis in giant cells and degeneration in spongiotrophoblasts were detected.
Bone measurement evaluation of the GD20 group fetal skeletons of the control and TBBP-A application groups, which were stained with Alcian Blue and Alizarin red, was performed. In skeletal measurements, a significant decrease was observed in x-y axis skeletal diameter, right-left scapula, right-left humerus, right-left radius, right-left ulna, right ilium, right femur, left tibia real lengths compared to the control group.
Serum FSH values increased statistically in the GD20 group. Serum progesterone and LH values increased statistically in the GD15 group. Although there are increases and decreases in serum estrogen values, they are not statistically significant. Estrogen hormone values of GD20 female fetuses decreased statistically in the 20mg/kg administration group compared to the control group, while the 200mg/kg administration group showed a statistical increase compared to the control group. GD20 male fetuses showed a statistical increase in testosterone hormone levels.
As a result, the effects of TBBP-A administered orally to pregnant women caused both maternal and fetal negativities. Considering the effect on the hormones examined together with the detailed histopathological examination of the placental tissue, endocrine disruption has been shown.
