en Nervous system (others) Others Experimental research article Experimental research article Introduction: Gonadotropin inhibitory hormone (GnIH) and Agouti-related peptide (AgRP) are orexigenic peptides expressed in the arcuate nucleus (Arc) of the hypothalamus in the ewe. In addition, effects of GnIH and AgRP on the regulation of gonadotropin releasing hormone secretion have been shown in some mammals. The objective of the present study was to investigate the coexpression of GnIH and AgRP in Arc of the ewe hypothalamus. Methods: Nine ewes were divided into follicular, luteal, and ovariectomised groups (n = 3 each group) and the number of neurons that express GnIH and AgRP and the percentage of coexpression of these two peptides in the Arc of each group was estimated by using immunohistochemistry. Results: In different ovarian conditions of ewes, 19 to 32 percent of GnIH and AgRP neurons were coexpressed in the Arc of the hypothalamus. Conclusion: Results of the present study showed a possible cooperative role of AgRP and GnIH in the Arc of the hypothalamus in regulation of ovarian function in ewe. Gonadotropin inhibitory hormone, Agouti-related peptide, Arcuate nucleus, Ewe 201 209 http://ppj.phypha.ir/browse.php?a_code=A-10-393-3&slc_lang=en&sid=1 Mohammad Reza Jafarzadeh Shirazi mrjaafarzadeh@yahoo.com 320031947532846009128 320031947532846009128 No Department of Animal Sciences, School of Agriculture, Shiraz University, Shiraz, Iran Amin Tamadon tamadon@shirazu.ac.ir 320031947532846009129 320031947532846009129 No Stem Cell and Transgenic Technology Research Center, Shiraz University of Medical Sciences & Department of Animal Health Management, School of Veterinary Medicine, Shiraz University, Shiraz, Iran Mohammad Reza Namavar namavarm@sums.ac.ir 320031947532846009130 320031947532846009130 Yes Department of Anatomical Sciences, School of Medicine & Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran