JOURNAL BROWSE
Search
Advanced SearchSearch Tips
Intravenous Orexin Reduces LH Secretion in Castrated Camelus Dromedaries Fed a Sub-maintenance Diet
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Intravenous Orexin Reduces LH Secretion in Castrated Camelus Dromedaries Fed a Sub-maintenance Diet
Khazali, Homayoun;
  PDF(new window)
 Abstract
It has been shown that orexin has an inhibitory effect on gonadotropin secretions in non-ruminant animals. The goal of this study was to determine whether orexin affects LH, and FSH secretions in the camel, as a pseudo-ruminant animal, under different dietary energy content. Sixteen castrated camels were randomly divided into 4 groups. Animals in groups 1 and 2 were fed 100% and animals in groups 3 and 4 were fed 50% energy content in their diet for 20 days. After 20 days, animals in groups 1 and 3 received infusions of 1 orexin and groups 2 and 4 received infusions of 2 orexin into their jugular vein. Blood samples were collected from the jugular vein every 20 minutes from 4 h before the first infusion of orexin until 4 h after the last orexin infusion. Lower dietary energy intake and infusions of 2 but not 1 orexin significantly (p<0.01) decreased the mean plasma concentrations and pulse amplitudes of LH of the animals. Infusion of 1 and 2 orexin did not change the secretions of LH of the animals fed NE. Different energy dietary intake and infusion of 1 and 2 orexin did not change the mean plasma concentrations of FSH of the animals in all groups. Infusions of 1 and 2 orexin significantly (p<0.01) decreased the glucose levels of animals fed LE but not in NE fed animals. Additionally, plasma glucose levels of the LE-fed animals in groups 3 and 4 were significantly (p<0.01) lower than those of the animals in groups 1 and 2 fed NE diet. The results of this experiment indicated that orexin may negatively affect LH and FSH in camels with negative energy balance, but not in those with positive energy balance.
 Keywords
Orexin;LH;FSH;Camel;
 Language
English
 Cited by
 References
1.
AFRC. Energy and protein requirements of ruminants. An advisory manual prepared by the AFRC technical committee on responses to nutrients. 1995. 2nd ed. CAB International, Wallingford, UK

2.
Al-Barazanji, K. A., S. Wilson, J. Baker, D. S. Jessop and M. S. Harbuz. 2001 Central orexin-A activates hypothalamicpituitaryadrenal axis arginine vasopressin neurones in conscious rats. J. Neuroendocrinol. 13:421-424 crossref(new window)

3.
Antoine, C., B. Delaleu, A. Locatelli, P. Bouchard, J. P. Gautron, N. P. Evans, F. J. Karsch and V. Padmanabhan. 1995. Nature and bioactivity of gonadotropin-releasing hormone (GnRH) secreted during the GnRH surge. Endocrinology 136:3452-3460 crossref(new window)

4.
Antunes, V. R., G. Brailoiu, E. H. Kwok, P. Scruggs and N. J. Dun. 2001. Orexins/hypocretins excite rat sympathetic preganglionic neurons in vivo and in vitro. Am. J. Physiol. Regul. Integr. Comp. Physiol. 281:1801-1807

5.
Backberg, M., G. Hervieu, S. Wilson and B. Meister. 2000. Orexin receptor-1 (OX-R1) immunoreactivity in chemically identified neurons of the hypothalamus: focus on orexin targets involved in control of food and water intake. Eur J Neurosci. 15:315-328 crossref(new window)

6.
Balasko, M., Z. Szelenyi and M. Szekely. 1999. Central thermoregulatory effects of neuropeptide Y and orexin A in rats. Acta Physiol. Hung. 86:219-222

7.
Boukhliq, R., R. L. Goodman, S. J. Berriman, B. Adrian and M. N. Lehman. 1999. A subset of gonadotropin-releasing hormone neurons in the ovine medial basal hypothalamus is activated during increased pulsatile luteinizing hormone secretion. Endocrinology 12:5929-5936 crossref(new window)

8.
Date, Y., Y. Ueta, H. Yamashita, H. Yamaguchi, S. Matsukura, K. Kangawa, T. Sakurai, M. Yanagisawa and M. Nakazato. 1999. Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems. Proc. Natl. Acad. Sci. USA. 96:748-753 crossref(new window)

9.
Dun, N. J. and J. K. Chang. 1999. Orexin A-like immunoreactivity in the rat brain. Neurosci. Lett. 260:161-164 crossref(new window)

10.
Ehmke, H. and A. Just. 2003. The orexins: linking circulatory control with behavior. Am. J. Physiol. Regul. Integr. Comp. Physiol. 285:519-521

11.
Furuta, M., T. Funabashi and F. Kimura. 2002. Suppressive action of orexin A on pulsatile luteinizing hormone secretion is potentiated by a low dose of oestrogen in ovariectomised rats. Neuroendocrinology 75:151-157 crossref(new window)

12.
Ghatei, M. A. and S. R. Bloom. 2003. Orexin A interactions in the hypothalamo-pituitary gonadal axis. Endocrinology 142:5294-5302 crossref(new window)

13.
Goncz, E., M. Strowski, C. Grötzinger, K. Nowak, P. Kaczmarek, M. Sassek, S. Mergler, B. El-Zayat, M. Theodoropoulou, G. Stalla, B. Wiedenmann and U. Plockinger. 2008. Orexin-A inhibits glucagon secretion and gene expression through a Foxo1-dependent pathway. Endocrinology 149:1618-1626 crossref(new window)

14.
Hagan, J. J., R. A. Leslie and S. Patel. 1999. Orexin A activates locus coeruleus cell firing and increases arousal in the rat. Proc. Natl. Acad. Sci. 96:10911-10916 crossref(new window)

15.
Horvath, T. L., C. Peyron, S. Diano, A. Ivanov, G. Aston-Jones, T. S. Kilduff and A. N. van Den Pol. 1999. Hypocretin (orexin) activation and synaptic innervation of the locus coeruleus noradrenergic system. J. Comp. Neurol. 415:145-159 crossref(new window)

16.
Jones, D. N., J. Gartlon and F. Parker. 2001. Effects of centrally administered orexin-B and orexin-A: a role for orexin-1 receptors in orexin-B induced hyperactivity. Psychopharmacology 153:210-218 crossref(new window)

17.
Khazali, H. 1992. Postweaning anestrus in the sows fed different energy content in diet. Ph. D. thesis. University of Illinois, Champaign-Urbana

18.
Kohsaka, A., H. Watanobe, Y. Kakizaki, T. Suda and H. B. Schio. 2001. A significant participation of orexin-A, a potent orexigenic peptide, in the preovulatory luteinizing hormone and prolactin surges in the rat. Brain Res. 898:166-170 crossref(new window)

19.
Kok, S. W., S. Roelfsema, G. J. Overeem, M. Lammers, A. Frolich, E. Meinders and M. Pijl. 2004. Pulsatile LH release is diminished, whereas FSH secretion is normal, in hypocretindeficient narcoleptic men. Am. J. Physiol. Endocrinol. Metab. 464:630-636

20.
Leibowitz, S., A. Akabayashi and M. Wang. 1998. Obesity on a high-fat diet: Role of hypothalamic galanin in neurons of the anterior paraventricular nucleus projecting to the median eminence. J. Neurosci. 18:2709-2719

21.
Marsoobian, V., M. Grosvenor, M. Jacob and E. Ipp. 1995. Verylow-energy diets alter the counterregulatory response to falling plasma glucose concentrations. Am. J. Clin. Nutr. 61:373-378

22.
Meghan, M. and K. Samson. 2003 .The other side of the orexins: endocrine and metabolic actions. Am. J. Physiol. Endocrinol. Metab. 284:13-17

23.
Merriam, G. R. and K. W. Wachter. 1982. Algorithms for the study of episodic hormone secretion. Am. J. Physiol. 243:310-318

24.
Mitsuma, T., Y. Hirooka and Y. Mori. 1999. Effects of orexin A on thyrotropin-releasing hormone and thyrotropin secretion in rats. Horm. Metab. Res. 31:606-609 crossref(new window)

25.
Nowak, K. W., M. Z. Strowski, M. M. Switonska, P. Kaczmarek, V. Singh, M. Fabis, P. Mackowiak, M. Nowak and L. K. Malendowicz. 2005. Evidence that orexins A and B stimulate insulin secretion from rat pancreatic islets via both receptor subtypes. Int. J. Mol. Med. 15:969-972

26.
Overeem, S., S. W. Kok ans G. J. Lammers. 2005 Somatotropic axis in hypocretin-deficient narcoleptic humans: altered circadian distribution of GH-secretory events. Am. J. Physiol. Endocrinol. Metab. 284:641-647

27.
Pelletier, J., D. H. Garnier, M. M. De Reviers, M. Terqui and R. O. Ortavant. 1982. Seasonal variation in LH and testosterone release in the rams of two breeds. J. Reprod. Fertil. 64:341-346 crossref(new window)

28.
Pu, S., M. R. Jain and P. S. Kalra. 1998. Regulatory peptides. J. Biol. Chem. 276:34631-34636

29.
Quedraogo, R., R. Naslaud and A. Kirshgesner. 2003. Glucose regulate the release of orexin from the pancreas. Diabetes 52:111-117 crossref(new window)

30.
Russell, S. H., C. J. Small and C. L. Dakin. 2001. The central effects of orexin-A in the hypothalamic-pituitary-adrenal axis in vivo and in vitro in male rats. J. Neuroendocrinol. 13:561-566 crossref(new window)

31.
Sasano, H. and T. Mouri. 2000. Orexin-A in the human brain and tumor tissues of ganglioneuroblastoma and neuroblastoma. Peptides 21:565-570 crossref(new window)

32.
Silverman, A., I. Livne and J. W. Witkin. 1994 The gonadotrophin releasing hormone (GnRH), neuronal systems: immunocytochemistry and in situ hybridization. In: The physiology of reproduction. 2nd ed (Ed. E. Knobil and J. D. Neill). New York: Raven; 1683-1706

33.
Tamura, T., M. Irahara, M. Tezuka, M. Kiyokawa and T. Aono. 1999. Orexins, orexigenic hypothalamic neuropeptides, suppress the pulsatile secretion of luteinizing hormone in ovariectomized female rats. Biochem. Biophys. Res. Commun. 264:759-762 crossref(new window)

34.
Towhidi, A., H. Khazali and M. Zhandi. 2007. Leptin is a metabolic signal for GnRH/LH/FSH axis in feed-restricted ewes. Asian-Aust. J. Anim. Sci. 20:1039-1048

35.
Traczyk, W. and F. Przekop. 1963. Methods of investigation of the function of the hypothalamus and hypophysis in chronic experiments in sheep. Acta Physiol. Pol. 14:217-226

36.
Willie, J. T., T. Sakurai, J. Hara, H. Takahira, H. K. Gershenfeld and M. Yanagisawa. 2002. Ectopic expression of orexin transgene alters body Weight and energy metabolism in mice. Society for Neuroscience Meeting, Orlando, FL. abstract 320