Pigmented macrophage aggregates: A toxic response in fish exposed to bleached‐kraft mill effluent?

Abstract

Abstract-An epidemiological study was conducted to evaluate whether the density of pigmented macrophage aggregates (PMAs) and the prevalences of preneoplastic and neoplastic lesions increased in fish captured downstream from a bleached-kraft pulp mill, causing induction of cytochrome P4501A enzymes (CYP1A). White suckers (Catostomus commersoni) sampled 10 and 95 km downstream from a bleached-kraft pulp mill in the St. Maurice River, Quebec, Canada, exhibited higher densities of PMAs relative to age in liver, spleen, and kidney than fish sampled 10 km upstream. White suckers were also sampled at three sites in the Gatineau River, Quebec, Canada, a reference river with a similar upstream/downstream ecological gradient but no pulp mill. In the Gatineau, density of PMAs was lower in the liver of fish sampled at the most downstream site, and there was no difference among sites in spleen and kidney. Higher growth rates have been documented at downstream sites of both rivers and thus cannot explain the increased density of PMAs observed at downstream sites of the St. Maurice River only. Density of PMAs did not differ between sexes or between fish with or without grossly visible parasites or granulomatous histological lesions. Although we cannot exclude the involvement of unknown infectious agents, density of PMAs appears to be a useful marker of bleached-kraft mill effluent (BKME) toxicity. Several known toxic effects of BKME could contribute to this response, including increased rates of lipid peroxidation associated with induced CYP1A and toxic hemolysis. Further field and laboratory studies are needed to evaluate whether the association between BKME exposure, induction of CYP1A, and increased density of PMA is consistent. Preneoplastic lesions were not observed in fish captured downstream of the pulp mill in the St. Maurice River, and only one case of biliary carcinoma was observed, at the most contaminated site.

Biotransformation, genotoxic, and histopathological effects of environmental contaminants in European eel (Anguilla anguilla L.)

“…A similar effect was previously noted in fish exposed to BKPME (Santos et al, 1990;Couillard and Hodson, 1996). According to Couillard and Hodson (1996), the presence in these effluents of resin acids or other hemolytic compounds may accelerate the rate of erythrocyte destruction, leading to the observed splenic hemosiderosis. The increment in hemolysis may result in a decrease in the number of mature erythrocytes in the circulating blood (Hibiya, 1982).…”

“…According to Myers et al (1987), this alteration is often associated with a degenerative-necrotic condition. More recently, Couillard and Hodson (1996) studied the proliferation of PMAs in BKPME-exposed fish and suggested that several known toxic effects of these effluents could contribute to this response, including CYP1A induction, toxic hemolysis, and impaired macrophage function. These statements are also applicable to splenic hemosiderosis.…”

Histopathology, ultrastructure and immunohistochemistry of Coregonus lavaretus hearts naturally infected with Ichthyocotylurus erraticus (Trematoda)

“…aggregations of MAs, EGCs and epithelioid cells) at the interface between host and parasite. The MAs were observed in histological sections of 14 powan hearts, and their proliferation has been frequently associated with both physiological and pathological factors including starvation, aging, intoxication and the presence of infectious disease (Vogelbein et al 1987, Couillard & Hodson 1996, Couillard et al 1999. The presence of MAs have been reported for Rivulus marmoratus (Poey) experimentally infected with the protozoan Calyptospora funduli Overstreet, Hawkins & Fournie, 1984(Vogelbein et al 1987) and also for Gasterosteus aculeatus infected with the microsporean Glugea anomala (Dezfuli et al 2004).…”

Histological and Histochemical Studies on the Early Developmental Stages of the Egyptian Toad <i>Bufo regularis</i> Reuss

“…Hepatic melanomacrophages appear to increase in number also with antigenic stimulation, and with otherfactors causing tissue breakdown [41]. Increased density of these macrophages has also been observed in experimentally treated fish [44], amphibians [45], and naturally polluted frogs [46].…”

“…Melanin is a complex polymer that can absorb and neutralize free radicals and other toxic agents [40] [43]. Melanomacrophages are focal accumulations of pigmented macrophages in liver, spleen and more rarely in kidneys of fishes [44] and also in liver of frogs [45]. These may contain four types of brown to black pigments, namely melanin, lipofuscin, ceroid, and hemosiderin/ferritin.…”