Thymic atrophy induced by methoxychlor in rat pups

Apoptosis in immunocytes induced by several types of pesticides

“…Several investigators have previously shown the immunomodulative action of these pesticides following in vivo or in vitro exposure. Takeuchi et al (2002Takeuchi et al ( , 2004 and Chapin et al (1997) demonstrated that methoxychlor affects the immune system, leading to atrophy of CD4 + CD8…”

“…Recent studies have found that the hazardous effects of several types of pesticides, such as organophosphorus and organochlorine, particularly affect the immune system (Blaylock et al, 1992;Chapin et al, 1997;Guo et al, 2002;Takeuchi et al, 2002;Nakadai et al, 2006;Li et al, 2007Li et al, , 2009Lopez et al, 2007;Jones and Miller, 2008). To study thymocyte apoptosis induced by environmental chemicals, we used the following: organophosphorus pesticides metamidophos and parathion, organochlorine pesticide methoxychlor, and the degradation product of fenitrothion, 3-methyl-4-nitrophenol (PNMC); dexamethasone was also tested here as a positive (i.e., known apoptosis-inducing) control.…”

“…+ double-positive T-lymphocytes in the thymus (Takeuchi et al, 2002(Takeuchi et al, , 2004. PNMC is a known degradation product of fenitrothion, an organophosphorus insecticide that is used widely in many countries (Bhushan et al, 2000); PNMC accumulates not only in the air, but also in soil and water (Nishioka et al, 1988;Nishioka and Lewtas, 1992).…”

Immunotoxicity in mice induced by short-term exposure to methoxychlor, parathion, or piperonyl butoxide

“…These three chemicals were chosen on the basis of previous studies; parathion markedly inhibits antigen-specific-IgM production (Casale et al, 1984), and we previously showed that methoxychlor exposure results in atrophy of CD4 + CD8 + T-lymphocytes in the thymus (Takeuchi et al, 2002(Takeuchi et al, , 2004Fukuyama et al, 2011b). Piperonyl butoxide is an agricultural insecticide synergist used mainly with pyrethroids (Carson et al, 1988;Mitsumori et al, 1996;Emerson et al, 2001).…”

Prior exposure to immunosuppressive organophosphorus or organochlorine compounds aggravates the TH1- and TH2-type allergy caused by topical sensitization to 2,4-dinitrochlorobenzene and trimellitic anhydride

“…Therefore, in a previous study, we focused on the organophosphorus pesticide parathion and organochlorine pesticide methoxychlor which were both known to play roles in the suppression of immune functions (Wiltrout et al, 1978;Casale et al, 1983Casale et al, , 1984Chapin et al, 1997;Staples et al, 1998;Takeuchi et al, 2002;Fukuyama et al, 2010b and2010c), and demonstrated that prior oral exposure to…”