Premature Luteal Regression Induced by Equine Chorionic Gonadotropin and Estrogen is Suppressed by Administration of Exogenous Interferon in Red Deer (Cervus Elaphus)1

Abstract

Superovulation of red deer hinds with eCG causes premature luteal regression by inducing follicular hypersecretion of estrogen that activates the luteolytic mechanism. Six groups of hinds (n = 8 per group) were treated with progesterone-impregnated intravaginal controlled internal drug-releasing (CIDR) devices for 14 days to synchronize estrus (CIDR device withdrawal = Day 0). Group 1 served as controls; group 2 received an i.m. injection of 1200 IU eCG at -72 h; group 3 received similar eCG treatment as well as i.m. injections of 0.25 mg estradiol benzoate (EDB) at 72, 84, 96, and 108 h; group 4 received twice-daily i.m. injections of 4 mg recombinant bovine interferon-alpha(I)1 (IFN) from Days 2 to 7; group 5 received IFN and eCG as above; group 6 received IFN, eCG, and EDB. Ovarian response was determined by laparoscopy on Days 14 and 15. Progesterone profiles were determined from thrice-weekly plasma samples from Days -14 to 28. Both the incidence of visible signs of luteal regression and the variation in the time of termination of the luteal phase (plasma progesterone < 1 ng/ml) were greater in eCG+EDB-treated hinds than in control, IFN-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). The ovulation rate in the eCG+EDB-treated hinds was less than that in the eCG-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). These results suggest that treatment with interferon, the putative embryonic pregnancy recognition signal, suppresses premature luteal regression induced by hypersecretion of estrogen following treatment with eCG.

Comparing two different superovulation protocols on ovarian activity and fecal glucocorticoid levels in the brown brocket deer (Mazama gouazoubira)

“…Other factors, including the high concentrations of estradiol secreted by anovulatory follicles, can also significantly reduce the rates of ovulation and total ovarian stimulation, as well as promoting premature regression of approximately 10% of the CL, similar to that previously reported for C. elaphus [8,16,49] and other domestic species [21,50]. Although both treatments resulted in a large number of anovulatory follicles, in eCG Treatment, four hinds (66.7%) presented repetition of behavioral estrus and signs of premature regression of CL, whereas in FSH Treatment, only two hinds (33.3%) showed the same signs, suggesting that premature regression is more closely associated with the use of eCG and its prolonged action than the mere occurrence of anovulatory follicles.…”

“…Among the available biotechnologies, stimulation of follicular growth to induce superovulation is essential to the success and efficiency of embryo transfer and in vitro fertilization programs [8], techniques that permit complete flexibility in sire/dam pairings [9]. Although multiple ovulation has been performed successfully in brown brocket [7], red ( Cervus elaphus [8-17], fallow ( Dama dama [11,13,18]), Pere David’s ( Elaphurus davidianus [15]), white-tailed deer ( Odocoileus virginianus , [19]), and some other domestic species [20,21], the procedure often results in highly variable superovulatory responses [10,20,21] and thus it is the weakest link in the chain of events required for successful multiple ovulation/embryo transfer technology (MOET) [22].…”

Incidence of Abnormal Corpus Luteum in Superovulated Ewes

“…The abnormal phenomenon of small, pale ovaries has also been reported as due to "premature luteal regression" in sheep [5], goats [6,7] and deer [8]. Regarding our previous report [4], the incidence of "premature luteal regression" was higher during the breeding season and in Merino × polled Dorset and South-Down breed ewes than during the non-breeding season and in Suffolk ewes, respectively .…”

Comparison of three protocols for superovulation of brown brocket deer (Mazama gouazoubira)

“…Although multiple ovulation has been performed successfully in red [ Cervus elaphus —Argo et al, ; Asher et al, ; Bainbridge et al, ; Fennessy et al, ,; Soler et al, ], fallow [ Dama dama —Asher et al, ; Fenessy et al, ; Morrow et al, ], Père David's [ Elaphurus davidianus —Argo et al, ], and white‐tailed deer [ Odocoileus virginianus —Waldhalm et al, ], the procedure often results in highly variable superovulatory responses and/or poor fertilization/embryo recovery rates [Fennessy et al, ]. The great variation in the superovulatory response is the weakest link in the chain of events required for successful MOET [Blanco et al, ].…”