Hormonal superovulation strongly affects the glycoprotein expression in ovine isthmus oviduct.

The oviduct isthmus is considered to be a sperm reservoir prior to ovulation in the reproductive tract of mammals. Ovarian steroids regulate the synthesis and secretion of specific molecules such as glycoproteins that are involved in the interactions between germ cells or embryos and oviductal epithelial cells. The objective of the present study was to investigate the effects on histmus glycoprotein pattern from hormonally stimulated ewes by means of lectin histochemistry. Isthmus fragments were separated from oviducts immediately after laparatomy, and, after fixed in 4% (w/v) neutral formalin, they were embedded in paraffin wax. Then, the sections were stained with a panel of lectins which revealed: 1) an increase of reactivity with MAL II, SNA, RCA120, SBA, GSA I-B4, GSA II, UEA I and LTA in the whole cytoplasm of ciliated and non-ciliated cells of hormonally treated females, 2) a reduction of DBA affinity in the luminal surface, 3) no staining pattern modification with PNA, KOH-sialidase (s)- PNA, HPA, Con A and KOH-s-WGA. These results indicate that exogenous gonadotropin administration for superovulation may alter the oligosaccharidic composition of glycoproteins produced in the ovine isthmus.