The objective of this study was to compare the concentrations of 17 beta-estradiol, progesterone, cAMP and cGMP in the follicular fluid of the largest cow follicle from the follicular phase of physiological sexual cycle and of follicles after synchronization of fut by cloprostenol (PGF2 alpha) and superovulation treatment with serum gonadotrophin (PMSG), in dependence on steroidal dominance of follicles. 2 x 25 cows, Slovak Pied x Lowland Black-Pied crossbreds with active corpus luteum, were subjected to superovulation treatment on the basis of rectal examination. Rut synchronization was achieved by cloprostenol of Czechoslovak provenience (Oestrophan Spofa), administered at the amount of 500 micrograms per dose. Serum gonadotrophin (Bioveta Concern, Ivanovice na Hané) at the amount of 2500 I. U. was administered forty-eight hours before the second dose of closprostenol. The animals were killed in slaughterhouses 48 hours later, or 72 hours later, since administration of the second dose of cloprostenol. The phase of the sexual cycle of control animals was determined by the method after Ireland et al. (1980) on the basis of morphological appearance of corpus luteum, presence of large preovulation follicle and by means of average concentrations of progesterone in blood serum. Aspirated follicular fluid was centrifuged using a cooling centrifuge at 3000 G. After separation, the supernatant was stored in a freezer at -18 degrees C until further treatment. 17 beta-estradiol and progesterone in the follicular fluid were determined by means of kits under the brand-names RIA-test-ESTRA (SI-125-9), or RIA-test-Prog (SI-125-6). Concentrations of cyclic nucleotides were determined by the RIA kits from the Institute vor Radioisotope Research, Production and Use (Prague), cAMP by 125J RIA kit (RIO12) and cGMP by 125J RIA (RIO42).(ABSTRACT TRUNCATED AT 250 WORDS)

Ustav experimentálnej veterinárnej medicíny Duklianských hrdinov Kosice