Short-term exposure of Chinook salmon (Oncoryhnchus tshawytscha) to o,p-DDE or DMSO during early life-history stages causes long-term humoral immunosuppression.

Abstract

We evaluated the effect of short-term exposures to a xenobiotic chemical during early life-history stages on the long-term immune competence of chinook salmon (Oncoryhnchus tshawytscha). Immersion of chinook salmon eggs in a nominal concentration of o,p´-dichlorodiphenyldichloroethylene (o,p´-DDE; 10 ppm) for 1 hr at fertilization followed by immersion in the same dose for 2 hr at hatch resulted in a significant reduction in the ability of splenic leukocytes from fish 1 year after treatment to undergo blastogenesis upon in vitro stimulation with lipopolysaccharide. We also observed that the vehicle, dimethyl sulfoxide (DMSO), caused a significant reduction in the ability of the splenic leukocytes to express surface immunoglobin M (SIgM) at this time. The concentration of o,p´-DDE in a pooled sample of whole fry from this treatment was 0.53 µg/g lipid 1 month after first feeding but was undetectable in all other treatments. Mortality rate, time to hatch, fish length, and weight were unaffected by treatment with o,p´-DDE. Similarly, sex ratios, gonadal development, and concentrations of plasma estradiol and 11-ketotestosterone were not affected by the treatment. In addition, we found no evidence that plasma lysozyme concentrations or the mitogenic responses of splenic leukocytes to concanavalin A or polyinosinic-polycytidylic acid were influenced by the treatment. In this experiment, a brief period of exposure to o,p´-DDE or DMSO during early development was able to induce long-term effects on humoral immune competence of chinook salmon. Such immunosuppression may increase susceptibility to disease, which may in turn be critical to regulating the population.

Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility

“…Metcalfe et al (2000) suggested that continuous exposure to endocrine active compounds such as o,p 0 -DDT must begin in ovo and continue throughout early development to affect reproductive endpoints in fish. (Milston et al, 2003). Visual and vibratory stimuli responses and routine swimming activity were impaired in Atlantic croaker larvae exposed to o,p 0 -DDT, which may decrease survival by increasing predation, decreasing feeding rates, or both (Faulk et al, 1999).…”

“…Dietary exposure to technical DDT has reduced survival in fish at multiple life stages (see review by Jarvinen and Ankley, 1999), and protective thresholds for whole-body total DDT concentrations have been recommended for early life stage, juvenile, and adult fish (Beckvar et al, 2005). In addition, exposure to p,p 0 -DDE, o,p 0 -DDT, and o,p 0 -DDE can affect behavior and disrupt the endocrine and immune systems in fish (Donohoe and Curtis, 1996;Ungerer and Thomas, 1996;Faulk et al, 1999;Milston et al, 2003;Papoulias et al, 2003;GarciaReyero et al, 2006;Barber et al, 2007). Exposure to p,p 0 -DDE has been associated with reduced reproductive success of bird populations; bald eagle (Haliaeetus leucocephalus) and osprey (Pandion haliaetus) are especially susceptible to eggshell thinning after exposure (Anderson and Hickey, 1972;Wiemeyer et al, 1984Wiemeyer et al, , 1988.…”

Relating chronic toxicity responses to population-level effects: A comparison of population-level parameters for three salmon species as a function of low-level toxicity

“…It is not clear whether immunosuppression in juvenile chinook leads to continued adverse effects at later ages or if open ocean chemical exposures result in sufficient tissue concentrations to trigger or maintain immune suppression. A recent laboratory study by Milston et al (2003) observed humoral immunosuppression 1 year after a two-step exposure (a 1-h exposure followed a month later by a 2-h exposure) of chinook embryos to sublethal concentrations of dichlorodiphenyldichloroethylene (DDE).…”

Ecological Risk Assessment of Organochlorine Pesticides in Surface Waters of Lake Taihu, China

“…These OCPs may have toxic effects on several non-target aquatic organisms, and even on aquatic ecosystems. Previous studies have reported that dietary exposure to OCPs led to reduced survival rates in fish at multiple life stages, including early life, the juvenile and adult stages (Barber et al 2007;Beckvar et al 2005;Milston et al 2003;Papoulias et al 2003). Exposure to DDTs may affect behavior and disrupt the endocrine and immune systems in fish (Barber et al 2007;Milston et al 2003;Papoulias et al 2003).…”