Vitamin E and Reproduction in Cultured Sea Bass:
A recent study was performed in order to observe and quantify the levels of vitamin E found in a species of sea bass known as Dicentrarchus labrax. The main method used in the study was high-pressure liquid chromatography. The study was initially divided into two distinct parts. The first part of the study was solely devoted towards the detection of vitamin E levels in the plasma of both male and female sea bass, whilst having in mind their body size. Both the seminal fluid and the eggs were examined for this purpose. Moreover, researchers also administered vitamin E to the sea bass and checked the amounts in the developing embryos.
The second part of the study was devoted to analyzing the variations of vitamin E levels during various phases of larval development. Each phase was thoroughly analyzed by the researchers. The results of the study show that there is a distinct correlation between the quantity of vitamin E found in plasma and the size of the body of the sea bass for both male and female test subjects. Moreover, researchers discovered that there are high levels of vitamin E before and after the fertilization process, in both the eggs and the seminal fluid. High levels of vitamin E were also found in the embryonic developmental phase and hatching phase. On the other hand, the results of the study show that both decreased survival and dead embryos had low levels of vitamin E.
Throughout the first four days of the larval development stage, the levels of vitamin E slowly decreased. However, starting with day 9 of the development stage, these levels increased steadily until the 40th day. Larvae suffering from teratogenic mutations showed much higher levels of vitamin E, when compared to normal larvae subjects. These results, of the two parts of the study, show that vitamin E is responsible for a powerful antioxidant defensive mechanism during the reproductive phase of the sea bass.
The results of the study emphasize an already well-known fact: antioxidant systems play a major role in protecting cells from damage inflicted by reactive oxygen species (ROS), such as superoxide, hydrogen peroxide, and lipid peroxide. Moreover, these antioxidants can also prevent the formation of these reactive oxygen species. According to previous studies, ROS are responsible for damaging the cellular membrane during fertilization, thus impairing the process. Moreover, ROS can also block a stage of the embryo development process.
Although vertebrates possess an innate, enzymatic antioxidant defense system, more often than not, they also require a non-enzymatic system as well. The enzymatic system consists of three major enzymes: catalase, superoxide dismutase, and glutathione peroxidase. The non-enzymatic system contains molecules that include vitamin E.