title: Prenatal zinc supplementation of zinc-adequate rats adversely affects immunity in offspring.
abstract: We previously showed that zinc (Zn) supplementation of Zn-adequate dams induced immunosuppressive effects that persist in the offspring after weaning. We investigated whether the immunosuppressive effects were due to in utero exposure and/or mediated via milk using a cross-fostering design. Pregnant rats with adequate Zn nutriture were supplemented with either Zn (1.5 mg Zn in 10% sucrose) or placebo (10% sucrose) during pregnancy (3 times/wk). At postnatal d 3, 4 pups of Zn-supplemented dams (Zn-P) were exchanged with 4 of placebo-supplemented dams (P-Zn). The remaining pups continued with their biological mothers (Zn-Zn and P-P). Pups were orally immunized with dinitrophenol ovalbumin-BSA and/or cholera toxin B subunit (CTB), and serum Zn concentrations and cellular and humoral responses were assessed. Pups of Zn-supplemented dams had higher serum Zn when fostered either by placebo- or Zn-supplemented dams compared to pups of placebo-supplemented dams (P < 0.01). Postnatal Zn exposure reduced the number of Peyer's patches in both the Zn-Zn and P-Zn groups (P < 0.01). Prenatal Zn exposure suppressed CTB- (P = 0.05) and BSA-specific proliferation response of Peyer's Patch lymphocytes (P = 0.07). Prenatal Zn exposure effects on the splenocyte cytokine response were differently influenced by fostering mothers' Zn status. Antigen presenting cell (APC) activity of splenocytes was lower in the Zn-Zn group than in the P-P group (P < 0.08). In conclusion, prenatal Zn exposure increases serum Zn levels in pups and suppresses antigen-specific proliferation and antibody responses and APC function, whereas postnatal exposure may suppress the mucosal immune reservoir.
authors.affiliation: International Centre for Diarrhoeal Diseases Research, Bangladesh, Dhaka-1212, Bangladesh.
authors.forename: Mohammad T K
authors.initials: MT
authors.lastname: Sharkar
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Jou
authors.forename: Mohammad B
authors.initials: MB
authors.lastname: Hossain
authors.forename: Bo
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: Charles B
authors.initials: CB
authors.lastname: Stephensen
authors.forename: Rubhana
authors.initials: R
authors.lastname: Raqib
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology; D001835:Body Weight; D016207:Cytokines / Q000378:metabolism; D019587:Dietary Supplements; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D009929:Organ Size; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D013054:Spectrophotometry, Atomic; D015032:Zinc / Q000008:administration & dosage* / Q000032:analysis
chemical_list: D016207:Cytokines; D015032:Zinc