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 lg/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.

Spatial and temporal variation in microcystin occurrence in wadeable streams in the southeastern United States

“…The persistent, measureable levels of microcystins observed in small headwater streams in the present study are a concern, given the potential consumption of aquatic life and water by terrestrial species, including humans . None of the microcystin concentrations we observed (3.2 µg/L maximum microcystin concentration) exceeded the World Health Organization moderate probability of acute adverse human health effects criterion for microcystins of 10 µg/L .…”

“…Microcystin-associated human illness has been documented in the United States by the Centers of Disease Control and Prevention [58], and microcystin-related human fatalities have been reported in other countries [40]. The persistent, measureable levels of microcystins observed in small headwater streams in the present study are a concern, given the potential consumption of aquatic life and water by terrestrial species, including humans [53,56,59,60]. None of the microcystin concentrations we observed (3.2 mg/L maximum microcystin concentration) exceeded the World Health Organization moderate probability of acute adverse human health effects criterion for microcystins of 10 mg/L [40].…”

A Global Analysis of the Relationship between Concentrations of Microcystins in Water and Fish

“…Different concentrations of MCs from the same sample have been previously detected with different analysis methods (e.g., Gkelis et al, 2006;Hardy et al, 2015). Comparison of MC concentrations in different organisms is difficult due to the variety of methods employed, protein binding affinity, and differences in pharmacokinetics in different organisms (Adamovskỳ et al, 2007;Zhang et al, 2013b). Analysis methods may be more comparable if they have similar extraction efficiencies, but many studies do not report this critical information.…”

Purification and physico-chemical study of serum albumins of two neotropical fish species from the São Francisco River Bassin, Brazil

“…In recent study, Zhang et al (2013) studied the total protein content in plasma from six kinds of mammals and fish and purified albumin. They found that total plasma protein and albumin content in mammals were nearly two times and four times higher than that in fish, respectively.…”