Effects of oral lead on serum proteins and the development of specific antibody response in young sheep
Hoffman, L.J.; Buck, W.B.; Quinn, L.Y.
American Journal of Veterinary Research 41(3): 331-337
1980
ISSN/ISBN: 0002-9645 PMID: 6989303 Document Number: 158346
Lambs (25) of Columbia-Rambouillet cross were divided into 5 equal groups which were given 0, 2, 4, 8 and 16 mg of Pb/kg of body wt, respectively, by mouth for 12 wk (5 days/wk). Pb was administered in the form of solubilized lead acetate by force-feeding, using plastic tubing and a syringe. Mean blood Pb concentrations for the 5 groups were 11.7, 37.2, 56.8, 67.7 and 99 .mu.g/dl, respectively, over the 6 mo. evaluation period. Serum protein fractions were evaluated at regular intervals by cellulose acetate electrophoresis and agar gel immunoelectrophoresis. This testing was initiated when the lambs were 5 days old and was continued until they were 6 mo. old. In the statistical analyses of absolute concentrations of total protein, albumin, .alpha.1-globulin, .alpha.2-globulin, .beta.-globulin and .gamma.-globulin, significant differences were seen among groups in some instances, but there was no definitive evidence for concluding that these alterations were an effect of increasing concentrations of Pb rather than normal biological variation and external stress factors. There were no detectable differences among groups of lambs in their development and maintenance of immunoglobulin (Ig) subgroups IgG and IgM, as determined by electrophoresis precipitin patterns. These 5 groups were also compared in their response to injections of heat-killed Serratia marcescens. There were no significant differences noted in passive hemagglutination titers among treatment groups, but during the actual period of immunization, the Pb-treated groups consistently had higher serum titers than the control group. None of the immunologic variables investigated in this study were consistently affected by the selected concentrations of oral Pb exposure. Under these research conditions, Pb apparently did not impose a state of immunologic deficiency in the sheep by altering specific antibody synthesis, nor by interfering with production or maintenance of serum proteins.