Hormesis and stage specific toxicity induced by cadmium in an insect model, the queen blowfly, Phormia regina Meig.

Abstract

Hormesis is an adaptive response, commonly characterized by a biphasic doseresponse that can be either directly induced, or the result of compensatory biological processes following an initial disruption in homeostasis [Calabrese and Baldwin, Hum. Exp. Toxicol., 21 (2002), 91]. Low and environmentally relevant levels of dietary cadmium significantly enhanced the pupation rate of blowfly larvae, while higher doses inhibited pupation success. However, dietary cadmium at all exposure levels adversely affected the emergence of the adult fly from the pupal case. Such findings represent the first report of a heavy metal displaying a hormetic-like biphasic response for pupation success, while at the same time displaying stage-specific toxicity at a later developmental period. These conclusions are based on substantial experimentation of over 1750 blowflies, in seven replicate experiments, involving 10 concentrations per experiment. These findings indicate the need to assess the impact of environmental stressors over a broad range of potential exposures as well as throughout the entire life cycle. AbstractThis is the first report of a heavy metal displaying a hormetic-like biphasic response for early developmental success, while at the same time displaying stage-specific toxicity at a later developmental stage.

Hormetic Effects of Heavy Metals in Aquatic Snails: Is a Little Bit of Pollution Good?

“…Similarly, marine amphipods exhibited increased growth and reproduction when exposed to relatively low doses of copper (Correia et al, 2001). At similar concentrations to the ones in the present study, sea scallops also exhibited a mild hormetic effect of cadmium on gamete maturation (Gould et al, 1989), and cadmiumexposed blowfly larvae display a hormetic-like biphasic response for pupation success (Nascarella et al, 2003). Finally, the cyanobacteria Spirulina platensis displays increased growth when exposed to low levels of nickel (Azeez and Banerjee, 1991).…”

“…In an extensive review of 4000 toxicological studies, Calabrese and Baldwin (1997 found that 350 of the studies revealed evidence of hormesis. They looked at a broad group of taxa, from bacteria to mammals, exposed to inorganics (Nascarella et al, 2003), organics (Laughlin et al, 1981;Zanuncio et al, 2003), heat (Hercus et al, 2003), and gamma radiation (Pollycove and Feinendegen, 2001). In order of frequency observed, hormetic effects were increase in growth, longevity (Cypser and Johnson, 2002;Rattan, 2001), reproduction, survival, and also metabolic effects.…”

Long-term exposure of the isopod Porcellionides pruinosus to nickel: Costs in the energy budget and detoxification enzymes

“…Calabrese and Baldwin, 2001;Nascarella et al, 2003;Calabrese and Blain, 2005;Lefcort et al, 2008). If the same hormetic response was present, we would expect that the higher concentration presented higher toxicity values (higher IBR values) and the lower concentration lower toxicity values than our control, which is not the case.…”

Hypoxia-cadmium interactions on rainbow trout (Oncorhynchus mykiss) mitochondrial bioenergetics: attenuation of hypoxia-induced proton leak by low doses of cadmium

“…Whether higher Cd doses combined with hypoxia would have resulted in stimulation of proton leak beyond that caused by hypoxia alone remains unknown. Nonetheless, the biphasic response observed in the present study is akin to hormesis (Calabrese and Baldwin, 2002;Calabrese and Baldwin, 2003;Nascarella et al, 2003), wherein low doses of stereotypically noxious (inhibitory) substances elicit beneficial (stimulatory) effects. A similar beneficial response was observed with regards to the combined action on complex I activity in that while hypoxia acting alone inhibited complex I activity, administration of 5 μmol l −1 Cd partially reversed this inhibition.…”