Autoradiographic detection of RNA and glycoprotein synthesis in epithelialcells of the oviduct in ovulated heifers

Heifers (n = 9) of the Black-Pied Holstein-Friesian breed were slaughtered on the 3rd, Gth and 9th day of the synchronized cycle, respectively (heat = day 0). Tissue samples from the ampullar part of the oviduct were collecte d immediately after slaughter and treated for histoautoradiographic (ARG) a nalyses. They were cultured for 20 min on air in 0.25 ml medium Dulbecco PB S at 38 degrees C enriched with 100 mu Ci/ml of [5-H-3] uridine (specific a ctivity 740 GBq/mM, UVVVR Prague) for detection of the RNA synthesis. For t he ARG detection of glycoprotein synthesis the samples of oviductal tissue were cultured for 60 or 240 min on air, respectively, in 0.25 mi medium Dul becco PBS at 38 degrees C to which 100 mu Ci/ml of L-[6-H-3] fucose (specif ic activity 0.55-1.1 TBq/mM, Amersham Int., Great Britain) was added. After incubation, the samples were fixed, dehydrated and embedded in Epon 812. S emithin (1 mu m) or ultrathin sections were coated with nuclear liquid emul sion K.5 or L.4, respectively. After one-month exposure they were developed using D 19 developer and after staining or contrasting they were observed using either light-microscopy or electron microscopy (using an electron mic roscope JEM 100 CX at 80 kV). Investigated autoradiograms revealed an inten sive synthesis of RNA in both cilliated as well as in secretory cells of th e oviduct epithelium. The intensity of RNA synthesis remains comparable dur ing the early luteal phase from the 3rd to the 9th day of the cycle. The gl ycoproteins, synthesized first in the Golgi apparatus in the supranuclear r egion were seen to move to the apical region of the epithelial cells later on. The most intensive autoradiographic reaction of newly synthesized glyco proteins was detected on the 3rd day of the cycle without an evident change on the 6th day but decreasing on the 9th day.