Evaluation of misoprostol effects during prenatal development in a zebrafish embryo modelBelina, Janta (Avtor) Sollner Dolenc, Marija (Mentor) Barenys, Marta (Komentor) misoprostolthromboxane receptor antagonist ICI-192605teratogenicityzebrafishDanio rerioMoebius syndromeMisoprostol is a synthetic analog of prostaglandin E1 that is frequently used around the world for the prevention and treatment of gastric ulcers, but due to its uterotonic properties, it has lately become popular as an abortifacient agent. It is considered relatively safe; however, misoprostol is often used incorrectly and under no medical supervision, which results in more failed abortions and in-utero exposure to misoprostol. Since misoprostol is considered a teratogen, it can have some harmful effects on the exposed fetus, such as craniofacial and limb abnormalities. It has also been associated with Moebius syndrome, a rare congenital disorder characterized by non-progressive facial weakness and limited abduction of the eyes. This Master's thesis aimed to study the effects that the drug produces and the mechanism by which it produces them. Furthermore, we wanted to relate the effects with symptoms of the Moebius syndrome. We performed two separate experiments, using a zebrafish model. Firstly, we exposed zebrafish embryos to misoprostol at concentration 5 µM and evaluated the craniofacial structures of the larvae at 72 hours post fertilization. The reason for using this exact concentration of misoprostol is the finding from previous experiments, that the lowest observed adverse effect concentration of misoprostol in zebrafish is 5 µM. The difference that 5 µM misoprostol produced were a thicker jaw, smaller eye, and increased distance from the eye to the nose. Secondly, we performed an optokinetic experiment, using an optokinetic rotary device that normally increases eye movement when rotating, on zebrafish larvae at 96 hours post fertilization and evaluated the effects of misoprostol on eye movement. The results showed that 5 µM misoprostol affects the eyes and produces an impairment of optokinetic response, as there was no significant increase in the eye movements of zebrafish in comparison to the control group. To study the mechanism of action of misoprostol, we used a thromboxane receptor antagonist. Therefore, in both experiments, zebrafish embryos were also exposed to misoprostol and thromboxane receptor antagonist ICI-192605 simultaneously. The concentration that we used was 12.5 µM, since it was found that at this concentration, ICI-192605 alone does not produce malformations. The antagonist reduced the morphological malformations in the craniofacial area. However, it did not reduce the alterations in optokinetic response. The results show that there is an involvement of the thromboxane receptor in the onset action of misoprostol on morphological structures; however, further experiments would need to be done to confirm the mechanism behind functional impairments.20232023-09-01 07:45:05Magistrsko delo/naloga148916sl