Vol.:(0123456789) 1 3 Journal of Comparative Physiology B https://doi.org/10.1007/s00360-018-1155-4 ORIGINAL PAPER Iron storage disease (hemochromatosis) and hepcidin response to iron load in two species of pteropodid fruit bats relative to the common vampire bat Iga M. Stasiak 1,2,4  · Dale A. Smith 1  · Tomas Ganz 3  · Graham J. Crawshaw 2  · Jutta D. Hammermueller 1  · Dorothee Bienzle 1  · Brandon N. Lillie 1 Received: 27 October 2017 / Revised: 14 March 2018 / Accepted: 14 March 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Hepcidin is the key regulator of iron homeostasis in the body. Iron storage disease (hemochromatosis) is a frequent cause of liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus), but reasons underlying this condition are unknown. Hereditary hemochromatosis in humans is due to defciency of hepcidin or resistance to the action of hepcidin. Here, we investigated the role of hepcidin in iron metabolism in one species of pteropodid bat that is prone to iron storage disease [Egyptian fruit bat (with and without hemochromatosis)], one species of pteropodid bat where iron storage disease is rare [straw-colored fruit bat (Eidolon helvum)], and one species of bat with a natural diet very high in iron, in which iron storage disease is not reported [common vampire bat (Desmodus rotundus)]. Iron challenge via intramuscular injection of iron dextran resulted in signifcantly increased liver iron content and histologic iron scores in all three species, and increased plasma iron in Egyptian fruit bats and straw-colored fruit bats. Hepcidin mRNA expression increased in response to iron administration in healthy Egyptian fruit bats and common vampire bats, but not in straw-colored fruit bats or Egyptian fruit bats with hemochromatosis. Hepcidin gene expression signifcantly correlated with liver iron content in Egyptian fruit bats and common vampire bats, and with transferrin saturation and plasma ferritin concentration in Egyptian fruit bats. Induc- tion of hepcidin gene expression in response to iron challenge is absent in straw-colored fruit bats and in Egyptian fruit bats with hemochromatosis and, relative to common vampire bats and healthy humans, is low in Egyptain fruit bats without hemochromatosis. Limited hepcidin response to iron challenge may contribute to the increased susceptibility of Egyptian fruit bats to iron storage disease. Keywords HAMP · Iron storage disease · Chiroptera · Iron metabolism · Hepcidin mRNA expression Abbreviations EFB Egyptian fruit bat CVB Common vampire bat SCFB Straw-colored fruit bat Communicated by I. D. Hume. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00360-018-1155-4) contains supplementary material, which is available to authorized users. * Brandon N. Lillie blillie@uoguelph.ca Iga M. Stasiak iga.stasiak@gov.sk.ca Dale A. Smith dalesmit@uoguelph.ca Tomas Ganz tganz@mednet.ucla.edu Graham J. Crawshaw crawshaw@bell.net Jutta D. Hammermueller jhammerm@uoguelph.ca Dorothee Bienzle dbienzle@uoguelph.ca 1 Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, ON N1G 2W1, Canada 2 Toronto Zoo, 361A Old Finch Avenue, Toronto, ON M1B 5K7, Canada 3 Department of Medicine, David Gefen School of Medicine at UCLA, CHS 37-055, Los Angeles, CA 90095-1690, USA 4 Present Address: Saskatchewan Ministry of Environment, Saskatoon, SK S7K 2H6, Canada