{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:31:19Z","timestamp":1760236279327,"version":"build-2065373602"},"reference-count":50,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,11,6]],"date-time":"2021-11-06T00:00:00Z","timestamp":1636156800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010739","name":"University of Camerino","doi-asserted-by":"publisher","award":["FAR 2014-2015"],"award-info":[{"award-number":["FAR 2014-2015"]}],"id":[{"id":"10.13039\/501100010739","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Apelin (APLN) is an adipokine mainly produced by adipose tissue and related to an individual\u2019s nutritional status as well as digestive apparatus functions. In this work, APLN and its receptor (APLNR) were investigated, by immunohistochemistry, in the abomasum and duodenum of 15 Comisana \u00d7 Appenninica adult sheep reared in a semi-natural pasture. Organ samples were collected after maximum pasture flowering (M \u00d7 F group) and after maximum pasture dryness (M \u00d7 D group); the experimental group (E \u00d7 p group) received a feed supplementation of 600 grams\/day\/head of barley and corn in addition to M \u00d7 D group feeding. APLN and APLNR were identified in the lining epithelium and the fundic gland chief cells of the abomasum. APLNR was observed in the lining epithelium, in the crypts and the serotonin secreting cells of the duodenum. Similar reactivity was observed between the M \u00d7 F and E \u00d7 p groups, while the M \u00d7 D group showed a lower intensity of immunostaining for both APLN and APLNR in all positive structures but the duodenal serotonin neuroendocrine cells. Hence, our findings show that the E \u00d7 p group presents a picture quite overlapped with M \u00d7 F and suggest that food supplementation has a maintaining effect on the apelinergic system expression in the investigated digestive tracts of the sheep.<\/jats:p>","DOI":"10.3390\/ani11113173","type":"journal-article","created":{"date-parts":[[2021,11,7]],"date-time":"2021-11-07T20:41:14Z","timestamp":1636317674000},"page":"3173","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["The Apelinergic System Immuno-Detection in the Abomasum and Duodenum of Sheep Grazing on Semi-Natural Pasture"],"prefix":"10.3390","volume":"11","author":[{"given":"Elisa","family":"Palmioli","sequence":"first","affiliation":[{"name":"Department of FISSUF, PhD Course in \u201cEthics of Communication, Scientific Research and Technological Innovation\u201d Medical-Health Curriculum, University of Perugia, Piazza G. Ermini, 1, 06123 Perugia, Italy"},{"name":"Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, 06126 Perugia, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6451-3751","authenticated-orcid":false,"given":"Cecilia","family":"Dall\u2019Aglio","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, 06126 Perugia, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michele","family":"Bellesi","sequence":"additional","affiliation":[{"name":"School of Biosciences and Veterinary Medicine, University of Camerino, Via Pontoni 5, 62032 Camerino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4319-9131","authenticated-orcid":false,"given":"Federico Maria","family":"Tardella","sequence":"additional","affiliation":[{"name":"School of Biosciences and Veterinary Medicine, University of Camerino, Via Pontoni 5, 62032 Camerino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sara","family":"Moscatelli","sequence":"additional","affiliation":[{"name":"School of Biosciences and Veterinary Medicine, University of Camerino, Via Pontoni 5, 62032 Camerino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4506-967X","authenticated-orcid":false,"given":"Paola","family":"Scocco","sequence":"additional","affiliation":[{"name":"School of Biosciences and Veterinary Medicine, University of Camerino, Via Pontoni 5, 62032 Camerino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8799-1200","authenticated-orcid":false,"given":"Francesca","family":"Mercati","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, 06126 Perugia, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1935","DOI":"10.1093\/jn\/136.7.1935S","article-title":"Adipose Tissue and Adipokines\u2014Energy Regulation from the Human Perspective","volume":"136","author":"Trayhurn","year":"2006","journal-title":"J. Nutr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1006\/bbrc.1998.9489","article-title":"Isolation and characterization of a novel endogenous peptide ligand for the human APJ receptor","volume":"251","author":"Tatemoto","year":"1998","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_3","first-page":"9170480","article-title":"Apelin in reproductive physiology and pathology of different species: A critical review","volume":"6","author":"Kurowska","year":"2018","journal-title":"Int. J. Endocrinol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/j.pharmthera.2005.04.001","article-title":"Emerging roles of apelin in biology and medicine","volume":"107","author":"Kleinz","year":"2005","journal-title":"Pharmacol. Ther."},{"key":"ref_5","first-page":"53","article-title":"The effect of exogenous apelin on the secretion of pancreatic juice in anaesthetized rats","volume":"63","author":"Kapica","year":"2012","journal-title":"J. Physiol. Pharmacol."},{"key":"ref_6","first-page":"R13-35","article-title":"The apelin receptor APJ: Journey from an orphan to a multifaceted regulator of homeostasis","volume":"219","author":"Lolait","year":"2013","journal-title":"J. Endocrinol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"206","DOI":"10.5455\/javar.2016.c158","article-title":"Adipokines as metabolic modulators of ovarian functions in livestock: A mini-review","volume":"3","author":"Mishra","year":"2016","journal-title":"J. Adv. Vet. Anim. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1764","DOI":"10.1210\/en.2004-1427","article-title":"Apelin, a newly identified adipokine up-regulated by insulin and obesity","volume":"146","author":"Boucher","year":"2005","journal-title":"Endocrinology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.regpep.2005.05.003","article-title":"Apelin, orexin-A and leptin plasma levels in morbid obesity and effect of gastric banding","volume":"130","author":"Heinonen","year":"2005","journal-title":"Regul. Pept."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s12020-011-9507-9","article-title":"Apelin, diabetes, and obesity","volume":"40","author":"Dray","year":"2011","journal-title":"Endocrine"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1124\/pr.110.002949","article-title":"International Union of Basic and Clinical Pharmacology. LXXIV. Apelin receptor nomenclature, distribution, pharmacology, and function","volume":"62","author":"Pitkin","year":"2010","journal-title":"Pharmacol. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Mercati, F., Maranesi, M., Dall\u2019aglio, C., Petrucci, L., Pasquariello, R., Tardella, F.M., De Felice, E., and Scocco, P. (2018). Apelin system in mammary gland of sheep reared in semi-natural pastures of the central apennines. Animals, 8.","DOI":"10.3390\/ani8120223"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.theriogenology.2019.08.012","article-title":"Apelin system detection in the reproductive apparatus of ewes grazing on semi-natural pasture","volume":"139","author":"Mercati","year":"2019","journal-title":"Theriogenology"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Dall\u2019Aglio, C., Mercati, F., De Felice, E., Tardella, F.M., Kamphues, J., Cappai, M.G., and Scocco, P. (2020). Influence of Different Feed Physical Forms on Mandibular Gland in Growing Pigs. Animals, 10.","DOI":"10.3390\/ani10050910"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"7796","DOI":"10.1002\/jcp.27720","article-title":"Function and regulation of apelin\/APJ system in digestive physiology and pathology","volume":"234","author":"Huang","year":"2019","journal-title":"J. Cell Physiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.peptides.2013.03.024","article-title":"Regulation of feeding behavior, gastrointestinal function and fluid homeostasis by apelin","volume":"44","author":"Lv","year":"2013","journal-title":"Peptides"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.regpep.2005.01.013","article-title":"Apelin cells in the rat stomach","volume":"129","author":"Susaki","year":"2005","journal-title":"Regul. Pept."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1342","DOI":"10.1210\/en.2003-1116","article-title":"Apelin, a New Enteric Peptide: Localization in the Gastrointestinal Tract, Ontogeny, and Stimulation of Gastric Cell Proliferation and of Cholecystokinin Secretion","volume":"145","author":"Wang","year":"2004","journal-title":"Endocrinology"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.regpep.2009.07.016","article-title":"Ontogeny of apelin and its receptor in the rodent gastrointestinal tract","volume":"158","author":"Wang","year":"2009","journal-title":"Regul. Pept."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1208","DOI":"10.1006\/bbrc.2002.6575","article-title":"The effects of centrally administered apelin-13 on food intake, water intake and pituitary hormone release in rats","volume":"291","author":"Taheri","year":"2002","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1080\/1028415031000111273","article-title":"Inhibitory effect of apelin-12 on nocturnal food intake in the rat","volume":"6","author":"Hansen","year":"2003","journal-title":"Nutr. Neurosci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0304-3940(03)00351-3","article-title":"Intracerebroventricular injection of apelin-13 reduces food intake in the rat","volume":"353","author":"Sunter","year":"2003","journal-title":"Neurosci. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/S0378-1127(03)00124-5","article-title":"Browsing and grazing ruminants: Are they different beasts?","volume":"181","author":"Gordon","year":"2003","journal-title":"For. Ecol. Manag."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4006","DOI":"10.1002\/ece3.1661","article-title":"Foods, macronutrients and fibre in the diet of blue sheep (Psuedoisnayaur) in the Annapurna Conservation Area of Nepal","volume":"5","author":"Aryal","year":"2015","journal-title":"Ecol. Evol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.anifeedsci.2017.09.012","article-title":"Gastrointestinal functionality in animal nutrition and health: New opportunities for sustainable animal production","volume":"234","author":"Celi","year":"2017","journal-title":"Anim. Feed Sci.Technol."},{"key":"ref_26","first-page":"505","article-title":"Effect of long-term abandonment and spring grazing on floristic and functional composition of dry grasslands in a central Apennine farmland","volume":"61","author":"Catorci","year":"2013","journal-title":"Pol. J. Ecol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"8","DOI":"10.5424\/sjar\/2016143-9230","article-title":"Effects of summer rainfall variations on sheep body state and farming sustainability in sub-mediterranean pastoral system","volume":"14","author":"Scocco","year":"2016","journal-title":"Span. J. Agric. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1002\/jemt.22692","article-title":"Increase of forage dryness induces differentiated anatomical response in the sheep rumen compartments","volume":"79","author":"Scocco","year":"2016","journal-title":"Microsc. Res. Tech."},{"key":"ref_29","unstructured":"Eurell, J.A., and Frappier, B.L. (2013). Dellmann\u2019s Textbook of Veterinary Histology, Wiley-Blackwell."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"9","DOI":"10.4081\/ejh.2019.2993","article-title":"Epithelial expression of the hormone leptin by bovine skin","volume":"63","author":"Mercati","year":"2019","journal-title":"Eur. J. Histochem."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Maranesi, M., Di Loria, A., Dall\u2019Aglio, C., Piantedosi, D., Lepri, E., Ciaramella, P., and Mercati, F. (2020). Leptin System in Obese Dog Skin: A Pilot Study. Animals, 10.","DOI":"10.3390\/ani10122338"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.rvsc.2010.03.003","article-title":"Immunohistochemical evidence of Orexin-A in the pancreatic beta cells of domestic animals","volume":"89","author":"Pedini","year":"2010","journal-title":"Res. Vet. Sci."},{"key":"ref_33","unstructured":"Team, R.C. (2019). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1152\/physiolgenomics.00271.2005","article-title":"Transcriptomes of purified gastric ECL and parietal cells: Identification of a novel pathway regulating acid secretion","volume":"25","author":"Lambrecht","year":"2006","journal-title":"Physiol. Genom."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1046\/j.1439-0264.2001.00326.x","article-title":"Immunohistochemical study of the ontogeny of prochymosin- and pepsinogen-producing cells in the abomasum of sheep","volume":"30","author":"Kitamura","year":"2001","journal-title":"Anat. Histol. Embryol."},{"key":"ref_36","unstructured":"Barone, R., and Simoens, P. (2012). AnatomiaComparata Dei MammiferiDomestici, Edagricole-New Business Media."},{"key":"ref_37","first-page":"149","article-title":"Gastric neuroendocrine cells and secretory products","volume":"71","author":"Oberg","year":"1998","journal-title":"Yale J. Biol. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1038\/sj.ijo.0801228","article-title":"Secretory granules of endocrine and chief cells of human stomach mucosa contain leptin","volume":"24","author":"Cinti","year":"2000","journal-title":"Int. J. Obes. Relat. Metab. Disord."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/S0167-4889(99)00114-7","article-title":"Apelin, the natural ligand of the orphan receptor APJ, is abundantly secreted in the colostrum","volume":"1452","author":"Habata","year":"1999","journal-title":"Biochim. Biophys. Acta Mol. Cell Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.regpep.2007.02.002","article-title":"Increased colonic apelin production in rodents with experimental colitis and in humans with IBD","volume":"142","author":"Han","year":"2007","journal-title":"Regul. Pept."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.peptides.2013.08.005","article-title":"Apelin stimulates both cholecystokinin and glucagon-like peptide 1 secretions in vitro and in vivo in rodents","volume":"48","author":"Wattez","year":"2013","journal-title":"Peptides"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"261","DOI":"10.3280\/ECAG2018-002010","article-title":"Anatomy for economy: Starting from the rumen keratinization degree to enhance the farm income","volume":"20","author":"Scocco","year":"2018","journal-title":"Econ. Agro-Aliment."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Barbato, O., De Felice, E., Todini, L., Menchetti, L., Malfatti, A., and Scocco, P. (2021). Effects of Feed Supplementation on Nesfatin-1, Insulin, Glucagon, Leptin, T3, Cortisol, and BCS in Milking Ewes Grazing on Semi-Natural Pastures. Animals, 11.","DOI":"10.3390\/ani11030682"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1038\/nrgastro.2013.105","article-title":"Serotonin signalling in the gut-functions, dysfunctions and therapeutic targets","volume":"10","author":"Mawe","year":"2013","journal-title":"Nat. Rev. Gastroenterol. Hepatol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1016\/S0024-3205(97)00387-1","article-title":"5-HT receptor subtypes involved in the serotonin-induced inhibition of L-leucine absorption in rabbit jejunum","volume":"61","author":"Salvador","year":"1997","journal-title":"Life Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1051\/rnd:19890405","article-title":"Effect of serotonin on D-galactose transport across the rabbit jejunum","volume":"29","author":"Arruebo","year":"1989","journal-title":"Reprod. Nutr. Dev."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1111\/j.1748-1716.2008.01870.x","article-title":"The role of serotonin in intestinal luminal sensing and secretion","volume":"193","author":"Hansen","year":"2008","journal-title":"Acta Physiol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1053\/j.gastro.2005.02.011","article-title":"Serotonin inhibits Na+\/H+ exchange activity via 5-HT4 receptors and activation of PKC alpha in human intestinal epithelial cells","volume":"128","author":"Gill","year":"2005","journal-title":"Gastroenterology"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"11859","DOI":"10.1074\/jbc.M411553200","article-title":"Involvement of c-Src and protein kinase C delta in the inhibition of Cl(\u2212)\/OH\u2212 exchange activity in Caco-2 cells by serotonin","volume":"280","author":"Saksena","year":"2005","journal-title":"J. Biol. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1111\/j.1748-1716.2010.02175.x","article-title":"Apelin stimulation of duodenal bicarbonate secretion: Feeding-dependent and mediated via apelin-induced release of enteric cholecystokinin","volume":"201","author":"Purhonen","year":"2011","journal-title":"Acta Physiol."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/11\/11\/3173\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:26:54Z","timestamp":1760167614000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/11\/11\/3173"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,6]]},"references-count":50,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["ani11113173"],"URL":"https:\/\/doi.org\/10.3390\/ani11113173","relation":{},"ISSN":["2076-2615"],"issn-type":[{"type":"electronic","value":"2076-2615"}],"subject":[],"published":{"date-parts":[[2021,11,6]]}}}