Effet chez le porcelet d'une exposition à un régime co-contaminé en ...

INTRODUCTIONThe depletion of lymphocytes suggested a suppression of cell mediated immunity. Indeed, thecontact sensitivity reaction, was reduced in chicken fed the co-contaminated diet with an additiveinteraction between AF and OTA (Kalorey et al., 2005; Sakhare et al., 2007; Verma et al., 2004).However, Verma et al. (2004) observed that, with increasing doses of toxins, the interaction wentfrom additive to less than additive and to antagonist (Table 2).In order to analyze the effect of the mycotoxins on the humoral response, the antibodies titersagainst Newcastle disease, Sheep red blood cells or Infectious Bursal disease were measured (Kaloreyet al., 2005; Raju and Devegowda, 2002; Sakhare et al., 2007; Verma et al., 2004). Mono- and multicontaminateddiets decreased the humoral response, and interaction between AF and OTA showedeither an additive (Sakhare et al., 2007; Verma et al., 2004) or antagonistic interaction (Kalorey et al.,2005; Raju and Devegowda, 2002; Verma et al., 2004) (Table 2).Also reported the effect on complement activity, but a less than additive interaction was obtainedbetween OTA and AF (Richard et al., 1975) (Table 2).e) effects of AF and OTA on teratologyBoth AF and OTA are able to cross the placental barrier and demonstrated some teratogenicproperties in some species (Wangikar et al., 2004b; Wangikar et al., 2005)In two separate experiments, Edrington et al. (1995) showed that embryonic mortality increasedfollowing injection to combination of AF and OTA, but led to different types of interaction accordingto doses and experiments. He supposed these differences were related to variations in embryosensitivities among batches of eggs. By contrast, exposure of chicken embryos to the combination oftoxins did mostly result in a synergistic interaction in the number of abnormalities.Wangikar in 2004b and 2005 performed two large studies in rats and rabbits, respectively, wheremycotoxins were administered orally on days 6-18 of gestation. Both mycotoxins interfered with thebody wall formation leading to gastroschisis as observed in both the high OTA and high AFcombination groups (Wangikar et al., 2004b). In the co-exposed group, more severe cardiac lesionswere noticed (Wangikar et al., 2004b; Wangikar et al., 2005) but skeletal, and visceral anomalieswere reduced or absent, when compared to the mono-exposed groups. Similarly, the presence of AFseems to prevent the exencephaly and incomplete closure of the skull caused by OTA; and thepresence of OTA prevent the head abnormality and open eye caused by AF. Another study of thesame group also indicates that brain, kidney, and liver lesions were less severe in rats fetuses coexposedto AF and OTA than in mono-exposed animals (Wangikar et al., 2004a). Two mechanismswere proposed to explain these observations. The first hypothesis is that AF may inhibit themetabolism of OTA in the liver and increase its excretion. The second hypothesis is based on the30