Glutathione-S-transferases(GSTs) are a family of iso-functional enzymes that conjugate to a variety of electrophilic compounds in the cytoplasm of aerobic cells. Among three classess of GST isoenzymes GST-L (Basic, liver GST) and GST-P(Acidic,
placenta
GST) are basic and acidic from puified from the rat liver and placenta. Respectively. although these enzymes are known to be expressed in various and conditions, there has been no study related to the pregnancy.
Using polyclonal antibodies against GST-L and GST-P, the distribution pattern of these enzymes were studied in the tissues of pregnant rat particularly in the uterus, oviduct and placenta. These major GST isoenzymes were detected
immunohistochemically
by avidin biotin peroxidase method.
In the uterus, the surface epitheliumof endometrium showed positivity for GST-P, and it immunerecactivity increased as the gestation continued. In contrast, GST-L showed no change during pregnancy. In the endometrial stroma GST-L was positive
instead of
GST-P, and it increased with pregnancy duration. In the decidua, GST-P was detected at the peripheral zone while GST-L was expressed in central zone in early qestation period. In the placenta, GST-P was positive in the cytotrophoblast and giant
trophoblasts of basal placenta. Its immunoreactivity increased during pregnancy, reaching the peak between 13-16th day of gestation. In the ovary, GST-P was positive only in the oocyte while GST-L was ositive in the granulosa cells, theca cells
and
lutein cells. In the oviduct GST-L was positive only in the oocyte while GST-L was positive in the granulosa cells, theca cells and lutein cells. In the oviduct GST-L was expressed in the surface epithelium, and GST-P was not expressed.
In conclusion, endometrium, oviduct, and placenta express glutathione S-transferases, and their activities increase during the pregnancy.
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