Effect of steroid free equine follicular fluid on FSH secretion in seasonally anestrous ewes and on the onset of estrous induced with. PGF2&#945; in cyclic ewes

Joel Hernández Cerón; Clara Murcia Mejía; Javier Valencia Méndez; Susana Rojas Maya; Juan Zárate Martinez; Luis Zarco Quintero

1997, Number 2

Vet Mex 1997; 28 (2)

Effect of steroid free equine follicular fluid on FSH secretion in seasonally anestrous ewes and on the onset of estrous induced with. PGF2α in cyclic ewes

Joel Hernández Cerón, Clara Murcia Mejía, Javier Valencia Méndez, Susana Rojas Maya, Juan Zárate Martinez, Luis Zarco Quintero

Full text

How to cite this article

Language: English/Spanish
References: 29
Page: 117-121
PDF size: 440.29 Kb.

ABSTRACT

The objective of this study was to evaluate if the administration of steroid-free equine follicular fluid (EFF) suppresses FSH secretion in seasonally anestrous ewes, and ifit delays the onset of estrus after treatment with prostaglandin F2α in cyclic ewes. In the first experiment, 19 seasonally anestrous ewes were divided into two groups. The treated group (n = 10) was treated with 3 ml of EFF every 8 h for 5 days. The control group (n = 9) was treated with physiological saline solution. The EFF was previously treated with charcoal-dextran in order to remove steroid hormones. Blood samples for FSH determination were obtained from both groups every 4 h during the period of the EFF treatment. FSH concentration were compared between groups by a variance analysis for repeated measures that used treatment and time as independent variables. FSH concentrations were significantly lower in the ewes treated with EFF (P ‹ 0.05). In the second experiment 22 cyclic ewes were synchronized with a vaginal sponge containing 45 mg of fluorogestone acetate. On day 11, after the synchronized estrous, all animals were treated with 15 mg of PGF2α in order to induce luteal regression. Synchronized ewes were divided in two groups. Animals in the treated group (n = 11) were injected iv with 3 ml of EFF every 8 h for 72 h, starting on the day of the PGF2α administration. The ewes in the control group (n = 11) were given physiological saline solution. Estrous detection was carried out every 8 h using males fitted with an apron. The onset of estrous was considered to occur when the female accepted the male for the first time. The interval from PGF2‹ to the onset of estrous was significantly longer in the ewes receiving EFF (131 ± 9.9), than in the control group (44 ± 3.9). It is concluded that EFF treatment suppresses FSH concentrations in seasonally anestrous ewes, and delays the onset of synchronized estrous in cyclic ewes. This data indicates that EFF is a rich source of inhibin which is biologically active in the ewe.

REFERENCES

Baxter, G., O'Shea, T., Campbell, B. and Webb, R.: Effects of bovine follicular fluid (bFF) fractions, which delay oestrus in sheep and cattle, on proliferation and steroid production by cultured granulosa cells. J. Reprod. Fertil., 15 (Abstract Series):64 (1995).
Beard, A.P. and Hunter, M.G.: Effects of bovine follicular fluid and exogenous oestradiol on the GnRH-induced short luteal phase in anoestrous ewes. J. Reprod. Fertil., 100: 211-217 (1994).
Bergfelt, D.R. and Ginther, O.J.: Delayed follicular develop ment and ovulation following inhibition of FSH with equine fluid in the mare. Theriogenology, 24:99-109 (1985).
Campbell, B.K., Picton, H.M., Mann, G.M., McNeilly, A.S. and Baird, D.T.: The effect of steroid and inhibin-free ovine follicular fluid on ovarian follicle population and ovarian hormone secretion. J. Reprod. Fertil., 93:81-96 (1991).
Chemineau, P.: Plasma levels of LH, FSH, prolactin, oestradiol 17B and P₄ during natural and induced oestrus in the dairy goat. Theriogenology, 17: 313-322 (1982).
Findlay, J.K, Robertson, D.M. and Clarke, I.d.: Influence of dose and route of administration of bovine follicular fluid and sup pressive effect of purified inhibin (M 31 000) on plasma FSH concentrations in ovariectomized ewes. J. Reprod. Fertil., 80:455-461 (1987).
García, de M.E.: Modificaciones al Sistema de Clasificación Climatológica de Koeppen. 5a ed. Instituto de Geografía, Universidad Nacional Autónoma de México, México, D.F., 1973.
Ginther, O.J.: Folliculogenesis during the transitional period and early ovulation season in mares. J. Reprod. Fertil., 90: 311-320 (1990).
Gremmes, S.: The secretional profile of gonadotrophines in the mare following hormonal inteivention. Doktor Thesis. Tierärztliche Hochschule Hannover. Hannover. Germany, 1990.
Hunter, M.G., Hindle, J.E., McLeod, B.J. and McNeilly, A.S.: Treatment with bovine follicular fluid suppresses follicular development in gonadotrophin-releasing hormone-treated anoestrous ewes. J. Endocrinol., 119: 95-100 (1988).
Knight, P.G.: Identification and purification of inhibin and inhibin-related proteins. J Reprod. Fertil., 43: 111-123 (1991).
Knight, P.G.. Castillo, R.J. and Glencross, R.G.: Isolation from bovine follicular fluid (bFF) of a 32 kDalton molecule with potent inhibin-like biological activity (ILA). J. Endocrinol., 112 (Suppl. Abstr.): 52 (1987).
Knight, P.G. and Castillo, R.J.: Effects of bovine follicular fluid on gonadotrophin secretion in intact and chronically ovariectomized ewes before and after desensitization of pituitary gonadotrophs to gonadotrophin-releasing hormone. J. Endocrinol., 117: 431-439 (1988).
Larson, G.H., Mallory, D.S., Dailey, R.A. and Lewis, P.E.: Gonadotrophin concentrations, follicular development, and luteal function in pituitary stalk-transected ewes treated with bovine follicular fluid. J. Anim. Sci., 69: 410-4111 (1991).
Law, A.S., Baxter, G., Logue, D.N., O'Shea, T. and Webb, R.: Evidence for the action of bovine follicular fluid factor(s) other than inhibin in suppressing follicular development and delaying oestrus in heifers. J. Reprod. Fertil., 96: 603-616 (1992).
Leversha, L.J., Robertson, D.M., Vos de, F.L., Morgan, F.J., Hearn, M.T.W., Wettenhall, R.E.H., Findlay, J.K, Burger, H.G. and Kretser de, D.M.: Isolation of inhibin from ovine follicular fluid. J. Endocrinol., 113: 213-221 (1987).
McLeod, BJ. and McNeilly, A.S.: Suppression of plasma FSH concentrations with bovine follicular fluid blocks ovulation in GnRH-treated seasonally anoestrous ewes. J. Reprod. Fertil., 81: 187-194 (1987).
McNeilly, A.S.: Changes in FSH and the pulsatile secretion of LH during the delay in oestrus induced by treatment of ewes with bovine follicular fluid. J. Reprod. Fertil., 72: 165-172 (1984).
McNeilly, A.S.: Effect of changes in FSH induced by bovine follicular fluid and FSH infusion in the preovulatory phase on subsequent ovulation rate and corpus luteum function in the ewe. J. Reprod. Fertil., 74: 661-668 (1985).
Miller, K.F., Critser, J.K., Rowe, R.F. and Ginther, O.J.: Ovarian effects of bovine follicular fluid treatment in sheep and cattle. Biol. Reprod., 21:537-544 (1979).
Miller, K.F., Wesson, J.A. and Ginther, O.J.: Changes in concentrations of circulating gonadotrophins following administration of equine follicular fluid to ovariectomized mares. Biol. Reprod., 21: 867-872 (1979).
Miquelajauregui, G.E.M.: Efecto de la inhibina o flunixinmeglumine (finadyne) sobre la luteólisis en ovejas. Tesis de licenciatura. Fac. de Med. Vet. y Zoot. Universidad Nacional Autónoma de México. México, D.F., 1993.
Pulido, A,, Zarco, L., Galina, C.S., Murcia, C., Flores, G. and Posadas, E.: Progesterone metabolism during storage of blood samples from Gyr cattle: Effects of anticoagulant, time and temperature of incubation. Theriogenology, 35:965-975 (1991).
Quispe, T., Zarco, L., Valencia, J. and Ortiz, A.: Estrus synchronization with melengestrol acetate in cyclic ewes. Insemination with fresh or frozen semen during the first or second estrus post treatment. Theriogenology, 41: 1393-1409 (1994).
Roser, J.F., McCue, P.M. and Hoye, E.: Inhibin activity in the mare and stallion. Domes. Anim. Endocrinol., 11: 87-100 (1994).
Ruch Jr., F.E. and Knight, G.T.: Use of soluble and Staphylococcus aureus-immobilized second antibody compared in a radioimmunoassay for human α-fetoprotein. Clin. Chem., 26: 1133-1140 (1980).
Steel, R.G.D. y Torrie, J.H.: Biostadística. Principios y Procedimientos. McGraw-Hill, México, D.F., 1985.
Taya, K., Kaneko, H., Watanabe, G. and Sasamoto, S.: Inhibin and secretion of FSH in oestrous cycles of cows and pigs. J. Reprod. Fertil., 43 (Suppl.): 151-162 (1991).
Wallace, J.M. and McNeilly, A.S.: Increase in ovulation rate after treatment of ewes with bovine follicular fluid in the luteal phase of the oestrous cycle. J. Reprod. Fertil., 73: 505-515 (1985).