Suppression of the secondary FSH surge with bovine follicular fluid is associated with delayed ovarian follicular development in heifers

Turzillo, A. M.; Fortune, J.E.

doi:10.1530/jrf.0.0890643

Cited by 115 publications

(69 citation statements)

References 19 publications

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“…Consistent with previous findings [31], plasma concentrations of estradiol rose immediately after PG injection in all heifers. The peak level of plasma c on ce nt rat io ns o f es t rad io l in t he in hibi nimmunized group was about twice high as that in c o n t r ol s .…”

Section: Discussionsupporting

confidence: 92%

Ovarian Response and Hormonal Profiles in Heifers After Immunization and Re-immunization Against Inhibin .ALPHA.-Subunit.

Akagi

Shi

Kaneko

et al. 2002

Journal of Reproduction and Development

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Abstract. To explore a strategy for superovulation in heifers, effects of immunization and reimmunization of Japanese beef heifers against inhibin on ovarian response and hormonal profiles were investigated. On day 9 of the estrous cycle (day 0=day of estrus), ten heifers were primary injected intramuscularly (i.m.) either with inhibin vaccine (recombinant ovine inhibin α-subunit in oil emulsion, 125 µg/ml) or a placebo (Montanide:Marcol adjutant alone) followed by two booster injections at one estrous cycle intervals (immunized group). One year later, 3 injections of inhibin vaccine were given the same as in the first year (re-immunized group). Inhibin antibody titers in plasma of immunized heifers increased after the second injection of inhibin vaccine and in 3 out of 5 immunized heifers and multiple-ovulation (2.4 ± 0.6, n=5) was induced after the third injection. On the other hand, in the re-immunized heifers, the plasma inhibin antibody titers increased sharply after the first injection of inhibin vaccine and in 4 out of 5 re-immunized heifers multiple ovulation (4.4 ± 1.1, n=5) was induced after the first injection of inhibin vaccine. In all re-immunized heifers multipleovulation was induced after the third injection of inhibin vaccine (5.0 ± 1.1, n=5). The results also showed that the ovulation rates were positively correlated to circulating inhibin antibody titers and plasma levels of FSH. These results confirmed that active immunization against inhibin α-subunit induced multiple ovulation mainly by attenuation of the suppressive effect of inhibin on FSH secretion in heifers and indicated that re-immunization against inhibin was a good way to induce multiple-ovulation in cattle. Key words: Heifer, Active immunization, Inhibin, Superovulation, Cattle (J. Reprod. Dev. 48: [599][600][601][602][603][604][605] 2002) t is reported that immunoneutralization of inhibin to induce superovulation provides an alternative to current follicle stimulating hormone (FSH) or equine chorionic gonadotropin (eCG) t r eat m en t pr o t o c o ls fo r t h e pr o d uc t i o n o f transferable embryos in mammals [1][2][3][4][5][6][7][8]. Several studies have shown that active immunization of heifers against inhibin α-subunit [9-13] and passive

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Section: Discussionsupporting

confidence: 92%

Ovarian Response and Hormonal Profiles in Heifers After Immunization and Re-immunization Against Inhibin .ALPHA.-Subunit.

Akagi

Shi

Kaneko

et al. 2002

Journal of Reproduction and Development

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“…Beginning on the day of estrus, blood samples were collected by coccygeal venipuncture, and ultrasonographic examinations of ovaries were performed daily as previously described (Turzillo & Fortune 1990) using a realtime B-mode linear array ultrasound scanner equipped with a 7.5 MHz intrarectal probe (Aloka SSD-550V Zug, Switzerland). Examinations were recorded on videotape (digital Handycam, Hi8 Recording Tape, Sony Electronics, Park Ridge, NJ, USA).…”

Section: Ultrasonography and Collection Of Folliclesmentioning

confidence: 99%

Regulation of apoptosis in the atresia of dominant bovine follicles of the first follicular wave following ovulation

Valdez¹,

Cuneo²,

Turzillo³

2005

Reproduction

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During atresia of bovine follicles, granulosa cells are lost through the controlled form of cell death, apoptosis. The purpose of this study was to characterize the regulation of apoptotic death of granulosa cells in dominant bovine follicles during the first wave of follicular development. Dominant follicles were collected from Holstein heifers on days 4, 6 or 8 of the first follicular wave (n 5 5/day). Regulation of apoptosis in granulosa cells was examined by annexin V and propidium iodide staining; measurement of relative levels of mRNA encoding Bcl-2, Bcl-xL and Bax; and activity of caspase-3, -8 and -9. Steady-state levels of mRNA encoding four oxidative stress-response proteins were determined. Compared with day 4, the incidence of apoptotic and nonviable granulosa cells tended to increase on day 6, and numbers of nonviable cells were higher on day 8. The ratios of relative levels of mRNA encoding Bcl-2 to Bax and Bcl-xL to Bax were higher on day 6 than days 4 and 8. Activity of caspases-3 and -9 in granulosa cells did not change among the 3 days, while caspase-8 activity decreased on day 8 compared with days 4 and 6. Amounts of GSHPx, MnSOD and Cu/ZnSOD mRNA in granulosa cells were higher on day 8 than day 6. In theca interna, amounts of Cu/ZnSOD mRNA decreased between days 4 and 6. From the decreased production of estradiol and increased numbers of apoptotic and nonviable granulosa cells, we conclude that atresia of the dominant follicle is initiated between days 4 and 6 of the first follicular wave. However, apoptosis of granulosa cells does not appear to be initiated by changes in expression of oxidative stress-response proteins.

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“…Follicular fluid and plasma concentrations of oestradiol were determined using modifications of a radioimmunoassay kit (Second Antibody Oestradiol; Diagnostic Products Corporation, Los Angeles, CA; Turzillo and Fortune, 1990). The assay details for this laboratory have been reported for follicular fluid (Bergfelt et al, 2000) and for jugular (Ginther et al, 2000b) and caudal vena cava (Ginther et al, 2000a) plasma samples in cattle.…”

Section: Hormone Assaysmentioning

confidence: 99%

Effect of LH on circulating oestradiol and follicular fluid factor concentrations during follicle deviation in cattle

Ginther

Bergfelt²,

Beg³

et al. 2001

Reproduction

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Progesterone was used to reduce LH concentrations starting at the time when the largest follicle was > or = 5.7 mm in diameter or well before the expected start of follicle deviation (largest follicle > or = 8.5 mm in diameter). Plasma concentrations of LH, FSH and oestradiol were determined at 4 h intervals in control and progesterone-treated heifers (n = 8 per group). Concentrations of LH were lower (P < 0.05) in the progesterone-treated group, reflecting an absence of the transient increase in LH concentrations that encompasses follicle deviation. An increase in oestradiol and a continued decrease in FSH occurred at the start of follicle deviation in the control cows but not in the treated heifers. In a second experiment, follicular fluid of the two largest follicles of control and progesterone-treated heifers was sampled at the expected start of deviation (n = 8--10 per group). The concentrations of oestradiol, but not androstenedione and free insulin-like growth factor I (IGF-I), in follicular fluid were higher (P < 0.001) in the largest follicle than in the second largest follicle. Progesterone treatment reduced (P < or = 0.02) the concentrations of all three factors in follicular fluid and increased (P < 0.05) the concentrations of insulin-like growth factor binding protein 2 (IGFBP-2). These results confirm that oestradiol contributes to the continued decrease in FSH concentrations after the start of follicle deviation. Prevention of the transient LH increase, the oestradiol increase and the continued FSH decrease did not significantly alter the mean time or follicle diameters characteristic of expected follicle deviation. However, in some treated individuals (three of eight), the observed follicle deviation was delayed. In addition, these results indicate that the secretion of oestradiol into the circulation and the increase in oestradiol and IGF-I and decrease in IGFBP-2 concentrations in the follicular fluid at the start of deviation are functions of the transient increase in LH concentrations that encompasses follicle deviation.

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Suppression of the secondary FSH surge with bovine follicular fluid is associated with delayed ovarian follicular development in heifers

Cited by 115 publications

References 19 publications

Ovarian Response and Hormonal Profiles in Heifers After Immunization and Re-immunization Against Inhibin .ALPHA.-Subunit.

Ovarian Response and Hormonal Profiles in Heifers After Immunization and Re-immunization Against Inhibin .ALPHA.-Subunit.

Regulation of apoptosis in the atresia of dominant bovine follicles of the first follicular wave following ovulation

Effect of LH on circulating oestradiol and follicular fluid factor concentrations during follicle deviation in cattle

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