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Control of luteinizing hormone secretion in ewes by endogenous opioids and the dopaminergic system during short seasonal anoestrus: rôle of plane of nutrition

Published online by Cambridge University Press:  02 September 2010

F. Forcada ,
J. M. Lozano ,
J. A. Abecia  and
L. Zarazaga
F. Forcada
Affiliation:
Departamento de Producción Animal y Ciencia de los Alimentos, Universidad de Zamgoza, Miguel Servet 177, 50013 Zamgoza, Spain
J. M. Lozano
Affiliation:
Departamento de Producción Animal y Ciencia de los Alimentos, Universidad de Zamgoza, Miguel Servet 177, 50013 Zamgoza, Spain
J. A. Abecia
Affiliation:
Departamento de Producción Animal y Ciencia de los Alimentos, Universidad de Zamgoza, Miguel Servet 177, 50013 Zamgoza, Spain
L. Zarazaga
Affiliation:
Departamento de Producción Animal y Ciencia de los Alimentos, Universidad de Zamgoza, Miguel Servet 177, 50013 Zamgoza, Spain
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Abstract

The role of endogenous opioids and the dopaminergic system on the inhibition of luteinizing hormone (LH) secretion during early and late anoestrus, together with its modulation by the plane of nutrition were investigated in ewes with a short anoestrous season. In early anoestrus (22 March; day 0), two groups of ovariectomized, oestradiol-treated adult Rasa Aragonesa ewes, maintained under natural photoperiod at 41°N, were given enough food to provide 1·4 × (high; H; no. = 6) or 0·5 × (low; L; no. = 6) energy requirements for maintenance. The effects of administration of the opiate receptor antagonist naloxone (1 mg/kg at four 1-h intervals) (day 15) and of the dopaminergic2 receptor antagonist pimozide (0·08 mg/kg) (day 21) on LH secretion were assessed. A second experiment was carried out in late anoestrus (21 June) using the same protocol. A significant increase in LH pulse frequency after naloxone treatment for both H and L groups was detected in late anoestrus. Number ofLH pulses after naloxone injections in early anoestrus also increased in H (P < 0·05) and L ewes (P = 0·08). The effect of pimozide injection on mean LH pulse frequency was greater in early than in late anoestrus, especially in ewes receiving a high plane of nutrition (P < 0·05 and P = 0·07 for H and L ewes, respectively in April and P = 0·07 for H ewes in July). A significant increase of LH pulse amplitude was also detected in early anoestrus in H ewes (P < 0·01). These results provide evidence that endogenous opioid mechanisms are involved in the inhibition ofLH pulsatile release both in early and late anoestrus in ewes with a short seasonal anoestrus. The ability of pimozide to increase LH pulse frequency in early anoestrus could be enhanced by a high plane of nutrition in the breed studied.

Keywords

LHnaloxonenutritionpimozidesheep
Type
Research Article
Information
Animal Science , Volume 65 , Issue 2 , October 1997 , pp. 217 - 224
Copyright
Copyright © British Society of Animal Science 1997

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References

Abecia, J. A., Forcada, F. and Zarazaga, L. 1993a. A note on the effect of level of nutrition after weaning on the resumption of reproductive activity by ewes of two Spanish breeds lambing in spring. Animal Production 56: 273–276.Google Scholar
Abecia, J. A., Forcada, F., Zarazaga, L. and Lozano, J. M. 1993b. Effect of plane of protein after weaning on reproductive activity resumption in Rasa Aragonesa ewes lambing in late spring. Theriogenology 39:463–473.CrossRefGoogle ScholarPubMed
Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Brooks, A. N., Haynes, N. B., Yang, J. P. and Lamming, G. E. 1986a. Ovarian steroid involvement in endogenous opioid modulation of LH secretion in seasonally anoestrous mature ewes. Journal of Reproduction and Fertility 76: 709–715.CrossRefGoogle ScholarPubMed
Brooks, A. N., Lamming, G. E., Lees, P. D. and Haynes, N. B. 1986b. Opioid modulation of LH secretion in the ewe. Journal of Reproduction and Fertility 76: 693–708.CrossRefGoogle ScholarPubMed
Currie, W. D., Bauer, M. and Rawlings, N. C. 1993. The effect of naloxone on LHRH secretion from the median eminence of anestrous ewes. Animal Reproduction Science 31: 113–122.CrossRefGoogle Scholar
Currie, W. D. and Rawlings, N. C. 1987. Naloxone enhances LH but not FSH during various phases of the estrous cycle in the ewe. Life Sciences 41:1207–1214.CrossRefGoogle Scholar
Ebling, F. J. P., Schwartz, M. L. and Foster, D. L. 1989. Endogenous opioid regulation of pulsatile LH secretion during sexual maturation in the female sheep. Endocrinology 125:369–383.CrossRefGoogle ScholarPubMed
Ebling, F. J. P., Wood, R. I., Karsch, F. J., Vannerson, L. A., Suttie, J. M, Bucholtz, D. C, Schall, R. E. and Foster, D. L. 1990. Metabolic interfaces between growth and reproduction. III. Central mechanisms controlling pulsatile luteinizing hormone secretion in the nutritionally growth-limited female lamb. Endocrinology 126:2719–2727.CrossRefGoogle ScholarPubMed
European Community Commission. 1986. Scientific procedure and breeding of animals for use in scientific procedure establishments. Directive 86/609/EEC.Google Scholar
Forcada, F., Abecia, J. A. and Sierra, I. 1992. Seasonal changes in oestrous activity and ovulation rate in Rasa Aragonesa ewes maintained at two different body condition levels. Small Ruminant Research 8:313–324.CrossRefGoogle Scholar
Forcada, F., Abecia, J. A. and Zarazaga, L. 1991. A note on attainment of puberty of September-born early-maturing ewe lambs in relation to level of nutrition. Animal Production 53: 407–409.Google Scholar
Forcada, F., Zarazaga, L. and Abecia, J. A. 1995. Effect of exogenous melatonin and plane of nutrition after weaning on oestrous activity, endocrine status and ovulation rate in Salz ewes lambing in the seasonal anoestrus. Theriogenology 43: 1179–1193.CrossRefGoogle Scholar
Gayrard, V., Malpaux, B., Tillet, Y. and Thiery, J. C. 1994. Estradiol increases tyrosine hydroxilase activity of the A15 nucleus dopaminergic neurons during long days in the ewe. Biology of Reproduction 50:1168–1177.CrossRefGoogle Scholar
Goodman, R. L., Parfitt, D. B., Evans, N. P., Dahl, G. E. and Karsch, F. J. 1995. Endogenous opioid peptides control the amplitude and shape of gonadotropin-releasing hormone pulses in the ewe. Endocrinology 136: 2412–2420.CrossRefGoogle ScholarPubMed
Kao, C, Schaeffer, D. J. and Jackson, G. L. 1992. Different neuroendocrine systems modulate pulsatile luteinizing hormone secretion in photosuppressed and photorefractory ewes. Biology of Reproduction 46:425–434.CrossRefGoogle ScholarPubMed
Karsch, F. J., Bittman, E. L., Foster, D. L., Goodman, R. L., Legan, S. J. and Robinson, J. E. 1984. Neuroendocrine basis of seasonal reproduction. Recent Progress in Hormone Research 40:185–232.Google ScholarPubMed
Karsch, F. J., Dahl, G. E., Evans, N. P., Manning, J. M., Mayfield, K. P., Moenter, S. M. and Foster, D. L. 1993. Seasonal changes in gonadotropin-releasing hormone secretion in the ewe: alteration in response to the negative feedback action of estradiol. Biology of Reproduction 49: 1377–1383.CrossRefGoogle Scholar
Karsch, F. J., Dierschke, D. J., Weick, R. F., Yamani, T., Hotchkiss, J. and Knobil, E. 1973. Positive and negative feedback control by estrogen of luteinizing hormone secretion in the rhesus monkey. Endocrinology 92: 799–804.CrossRefGoogle ScholarPubMed
Le Corre, S. and Chemineau, P. 1993. Control of photoperiodic inhibition of luteinizing hormone secretion by dopaminergic and serotonergic systems in ovariectomized lle-de-France ewes supplemented with oestradiol. Journal of Reproduction and Fertility 97: 367–373.CrossRefGoogle Scholar
Legan, S. J., Karsch, F. J. and Foster, D. L. 1977. The endocrine control of seasonal reproductive function in the ewe: a marked change in response to the negative feedback action of estradiol on luteinizing hormone secretion. Endocrinology 101: 818–824.CrossRefGoogle Scholar
McShane, T. M., May, T., Miner, J. L. and Keisler, D. H. 1992. Central actions of neuropeptide-Y provide a neuromodulatory link between nutrition and reproduction. Biology of Reproduction 46:1151–1157.CrossRefGoogle ScholarPubMed
McShane, T. M., Petersen, S. L., McCrone, S. and Keisler, D. H. 1993. Influence of food restriction on neuropeptide Y, proopiomelanocortin, and luteinizing hormone-releasing hormone gene expression in sheep hypothalami. Biology of Reproduction 49: 831–839.CrossRefGoogle ScholarPubMed
Malpaux, B., Robinson, J. E., Wayne, N. L. and Karsch, F. J. 1989. Regulation of the onset of the breeding season of the ewe: importance of long days and of an endogenous reproductive rhythm. Journal of Endocrinology 122: 269–278.CrossRefGoogle ScholarPubMed
Malpaux, B., Wayne, N. L. and Karsch, F. J. 1988. Termination of the breeding season in the Suffolk ewe: involvement of an endogenous rhythm of reproduction. Biology of Reproduction 39:254–263.CrossRefGoogle ScholarPubMed
Mathews, M. V. and Murdoch, W. J. 1984. Increased secretion of luteinizing hormone in prepubertal ewes treated with an antagonist of opiates. Domestic Animal Endocrinology 1:167–173.CrossRefGoogle Scholar
Merriam, G. R. and Wachter, K. W. 1982. Algorithms for the study of episodic hormone secretion. American Journal of Physiology 243: E310–E318.Google Scholar
Meyer, S. L. and Goodman, R. L. 1985. Neurotransmitters involved in mediating the steroid-dependent suppression of pulsatile luteinizing hormone secretion in anestrous ewes: effects of receptor antagonists. Endocrinology 116: 2054–2061.CrossRefGoogle ScholarPubMed
Meyer, S. L. and Goodman, R. L. 1986. Separate neural systems mediate the steroid-dependent and steroid-independent suppression of tonic luteinizing hormone secretion in the anestrous ewe. Biology of Reproduction 35: 562–571.CrossRefGoogle ScholarPubMed
Montgomery, G. W., Martin, G. B. and Pelletier, J. 1985. Changes in pulsatile LH secretion after ovariectomy in llede-France ewes in two seasons. Journal of Reproduction and Fertility 73:173–183.CrossRefGoogle ScholarPubMed
Montgomery, G. W., Scott, I. C. and Johnstone, P. D. 1988. Seasonal changes in ovulation rate in Coopworth ewes maintained at different liveweights. Animal Reproduction Science 17:197–205.CrossRefGoogle Scholar
Pelletier, J., Gamier, D. H., De Reviers, M. M., Terqui, M. and Ortavant, R. 1982. Seasonal variation in LH and testosterone release in rams of two breeds. Journal of Reproduction and Fertility 64: 341–346.CrossRefGoogle ScholarPubMed
Recabarren, S. E., Zapata, P. and Parilo, J. 1990. Disappearance of opioidergic tone of LH secretion in underfed prepubertal sheep. Hormone and Metabolic Research 22: 225–228.CrossRefGoogle ScholarPubMed
Rhind, S. M. 1992. Nutrition: its effect on reproductive performance and its control in female sheep and goats. In Progress in sheep and goat research (ed. Speedy, A.W.), pp. 25–52. CAB International, Wallingford.Google Scholar
Rhind, S. M., McMillen, S. R. and McKelvey, W. A. C. 1991. Effects of levels of food intake and body condition on the sensitivity of the hypothalamus and pituitary to ovarian steroid feedback in ovariectomized ewes. Animal Production 52:115–125.Google Scholar
Robinson, J. E. and Karsch, F. J. 1984. Refractoriness to inductive day lengths terminates the breeding season of the Suffolk ewe. Biology of Reproduction 31: 656–663.CrossRefGoogle ScholarPubMed
Rondon, Z., Forcada, F., Zarazaga, L., Abecia, J. A. and Lozano, J. M. 1996. Oestrous activity, ovulation rate and plasma melatonin concentrations in Rasa Aragonesa ewes maintained at two different and constant body condition score levels and implanted or reimplanted with melatonin. Animal Reproduction Science 41:225–236.CrossRefGoogle Scholar
Schall, R. E., Ebling, F. J. P., Karsch, F. J. and Foster, D. L. 1991. Postpubertal maturation of endogenous opioid regulation of luteinizing hormone secretion in the female sheep. Biology of Reproduction 44: 760–768.CrossRefGoogle ScholarPubMed
Trout, W. E. and Malven, P. V. 1987. Effects of exogenous estradiol-17p and progesterone on naloxone-reversible inhibition of the release of luteinizing hormone in ewes. Journal of Animal Science 65:1602–1609.CrossRefGoogle ScholarPubMed
Weesner, G. D. and Malven, P. V. 1990. Intracerebral immunoneutralization of metenkephalin disinhibits release of pituitary luteinizing hormone in sheep. Neuroendocrinology 52: 382–388.CrossRefGoogle ScholarPubMed
Yang, K., Haynes, N. B., Lamming, G. E. and Brooks, A. N. 1988. Ovarian steroid hormone involvement in endogenous opioid modulation of LH secretion in mature ewes during the breeding and nonbreeding seasons. Journal of Reproduction and Fertility 83:129–139.CrossRefGoogle Scholar