title: Why mammals more susceptible to the hepatotoxic microcystins than fish: evidences from plasma and albumin protein binding through equilibrium dialysis.
abstract: To elucidate the interspecies variation of susceptibility to microcystins (MCs), fresh plasma and purified albumin from six kinds of mammals and fish were used in toxins-substances binding test. Protein contents in the test plasma were analyzed and the binding characteristics to MCs were compared. Two kinds of widely observed MCs, microcystin-LR (MC-LR) and microcystin-RR (MC-RR) were tested and data were collected through the method of equilibrium dialysis. It was found that total plasma protein and albumin content in mammals were nearly two times and four times higher than that in fish, respectively. In the test range of 0-100 μg/mL, binding rates of fish plasma to MCs were considered significant lower (p < 0.01) than that of mammals. And human plasma demonstrated the highest binding rate in mammals. In all the test species, plasma protein binding rates of MC-RR were significantly higher than MC-LR (p < 0.01). Besides, binding profiles of albumin were acquired under the protein content of 0.67 mg/mL. Human serum albumin demonstrated the highest affinity to MCs throughout the six species and differences among the other five species were considered not significant (p > 0.05). From the view of protein binding, it is concluded that both the variation of plasma protein composition and albumin binding characteristic could influence the existing form of MCs in circulation, change MCs utilization, alter MCs half-life and further contribute to the difference of susceptibility between mammals and fish.
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China. zhangwei0203@yahoo.cn
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Gaodao
authors.initials: G
authors.lastname: Liang
authors.forename: Laiyan
authors.initials: L
authors.lastname: Wu
authors.forename: Xun
authors.initials: X
authors.lastname: Tuo
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
mesh_terms: D000418:Albumins / Q000378:metabolism*; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D005399:Fishes / Q000097:blood*; D006207:Half-Life; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008322:Mammals / Q000097:blood*; D008387:Marine Toxins; D052998:Microcystins / Q000378:metabolism* / Q000633:toxicity; D011485:Protein Binding
chemical_list: D000418:Albumins; D001798:Blood Proteins; D008387:Marine Toxins; D052998:Microcystins; C063855:microcystin RR; C057862:cyanoginosin LR