In:
American Journal of Veterinary Research, American Veterinary Medical Association (AVMA), Vol. 61, No. 3 ( 2000-03-01), p. 339-344
Abstract:
Objective —To study effects of in vitro exposure of
bovine leukocytes to mercury, cadmium, and lead on phagocytosis, natural killer cell activity, and lymphocyte
proliferation. Sample Population —Leukocytes from 6 nonpregnant
Holstein heifers. Procedure —Leukocytes were exposed in vitro to the
aforementioned metals, and leukocyte functions were assessed. Results —Phagocytosis was suppressed by 10 −5 to
10 −7 M CdCl 2 and by 10 −5 and 10 −6 M HgCl 2 , but not
10 −7 M HgCl 2 nor 10 −4 to 10 −6 M PbCl 2 . Spontaneous and
concanavalin A- or phytohemagglutinin-stimulated proliferation of metal-treated bovine blood mononuclear
cells was not significantly different from that of nontreated control cells, except for enhanced spontaneous
proliferation in response to 10 −5 M HgCl 2 . When proliferation
was expressed as a stimulation index, a dosedependent increase of spontaneous proliferation was
observed in response to exposure to HgCl 2 and PbCl 2 .
Compared with response to 10 −6 or 10 −7 M CdCl 2 , reduction
of mitogen-induced and spontaneous proliferation was observed on exposure to 10 −5 M CdCl 2 . Natural
killer cell activity against yeast artificial chromosome target cells, evaluated by flow cytometry, was
decreased only in cells exposed to 10 −5 M HgCl 2 . Conclusion and Clinical Relevance —Bovine leukocytes
are susceptible to the immunomodulatory effects of in vitro exposure to heavy metals at concentrations
equal to or higher than those at which similar effects are seen for leukocytes from most other animal
species for which data are available for comparison. Exception is phagocytosis, which is severely affected
by low concentrations of CdCl 2 and HgCl 2 in cattle.
Reduction of defense mechanisms on exposure to metals could lead to increased susceptibility to potential
pathogens.( Am J Vet Res 2000;61:339–344)
Type of Medium:
Online Resource
ISSN:
0002-9645
DOI:
10.2460/ajvr.2000.61.339
Language:
Unknown
Publisher:
American Veterinary Medical Association (AVMA)
Publication Date:
2000
detail.hit.zdb_id:
2056942-7
SSG:
22
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