Journal article
Melanocortins may stimulate reproduction by activating orexin neurons in the dorsomedial hypothalamus and kisspeptin neurons in the preoptic area of the ewe
K Backholer, J Smith, IJ Clarke
Endocrinology | ENDOCRINE SOC | Published : 2009
DOI: 10.1210/en.2009-0604
Abstract
To further test the hypothesis that melanocortins stimulate the reproductive axis, we treated ewes with melanocortin agonist (MTII) in the luteal phase of the estrous cycle and during seasonal anestrus. Lateral ventricular infusion of MTII (10 μg/h) during the luteal phase increased LH secretion. Retrograde neuronal tracing in the brain showed few proopiomelanocortin or kisspeptin cells in the arcuate nucleus, but more than 70% of kisspeptin cells in the dorsolateral preoptic area (POA), projecting to the ventromedialPOAin whichGnRHcells are located. MTII infusion (20 h) was repeated in luteal phase ewes and brains were harvested to measure gene expression of preproorexin and kisspeptin. Exp..
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Funding Acknowledgements
[ "We thank Mr. B. Doughton, Ms. L. Morrish, and Ms. E. Gleeson for their technical assistance; and Dr. A. F. Parlow (National Hormone and Peptide Program, National Institute of Diabetes and Digestive and Kidney Diseases, Torrance, CA) for assay reagents.", "Address all correspondence and requests for reprints to: Prof. Iain Clarke, PhD, Department of Physiology, P. O. Box 13F, Monash University, Clayton, Victoria 3800, Australia. E-mail: iain.clarke@med.monash.edu.au.", "This work was supported by a grant from the National Health and Medical Research Council of Australia (to I.J.C.)." ]