title: Characterization of adiponectin concentrations and molecular weight forms in serum, seminal plasma, and ovarian follicular fluid from cattle.
abstract: Adiponectin (AdipoQ), an adipocyte-derived hormone, is one of the most abundant adipokines in the blood circulation. Adiponectin has various metabolic functions, such as improving insulin sensitivity in humans and rodents. The role of AdipoQ in reproduction is not yet fully understood, but the expression of AdipoQ in reproductive tissues has been observed in various animals and humans, including chicken testis, bovine ovary, and human placenta. The objective of this study was to characterize AdipoQ in the bovine body fluids related to reproduction. Therefore, we evaluated the seminal plasma (SP) from breeding bulls (n = 29) and follicular fluid (FF) from heifers (n = 14), and we also collected blood samples from these animals. In addition, blood samples from other bulls (n = 30) and heifers (n = 14) were assayed for AdipoQ. The concentrations were assessed using a bovine-specific ELISA, and the molecular weight (MW) pattern of the AdipoQ protein was estimated by the Western blot analysis. The SP AdipoQ concentrations were approximately 180-fold lower compared with that in the serum concentrations. Furthermore, the AdipoQ concentrations in the serum and SP were positively correlated. The MW patterns of AdipoQ in the serum and SP were different such that the high MW form of AdipoQ was more abundant in the SP than serum. The AdipoQ concentrations in the serum and SP also increased with age: old bulls (>6 years) had higher AdipoQ concentrations in the serum and SP than bulls aged 24 months or lesser (P < 0.05). In the FF, the AdipoQ concentrations were 1.6-fold lower than those in the corresponding serum samples, and the concentrations in the serum and FF were not correlated (P > 0.1). In the FF, only the middle MW forms of AdipoQ were detectable by Western blotting. The MW pattern in the serum did not differ between the sexes. Our data provide both the AdipoQ concentration and the MW patterns for bovine body fluids related to reproduction.
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Bonn, Germany.
authors.forename: Johanna F L
authors.initials: JF
authors.lastname: Heinz
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Bonn, Germany; Division of Physiology, Reproduction and Shelter Management, Central Institute for Research on Goats, Mathura, Makhdoom, Uttar Pradesh, India.
authors.forename: Shiva P
authors.initials: SP
authors.lastname: Singh
authors.affiliation: Rinder Union West (RUW), Borken, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Janowitz
authors.affiliation: Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hoelker
authors.affiliation: Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
authors.affiliation: Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
authors.affiliation: Institute of Animal Science, Physiology & Hygiene Unit, University of Bonn, Bonn, Germany. Electronic address: sauerwein@uni-bonn.de.
authors.forename: Helga
authors.initials: H
authors.lastname: Sauerwein
mesh_terms: D052242:Adiponectin / Q000097:blood / Q000378:metabolism*; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism; D008297:Male; D012661:Semen / Q000378:metabolism; D044967:Serum / Q000378:metabolism
chemical_list: D052242:Adiponectin
keywords: Adiponectin; Follicular fluid; Seminal plasma