Biomaterial Database

Immunotoxicological assessment of methyl parathion in female B6C3F1 mice. 1998

P L Crittenden, and R Carr, and S B Pruett

Department of Biological Sciences, Mississippi State University, Mississippi State, USA.

Methyl parathion is a widely used agricultural insecticide, and the recent unlicensed use of this compound in homes has led to the evacuation of approximately 1100 persons in Mississippi. Although the primary concern in such cases of acute exposure is neurotoxicity, a few organophosphorus compounds apparently have immunotoxic effects at dosages that do not produce neurotoxic symptoms. The purpose of the present study was to determine if this is the case for methyl parathion. Female B6C3F1 mice were exposed to methyl parathion by gavage, daily for 7, 14, 2 1, or 28 d (at 6 mg/kg/d). Exposure for 14-28 d produced significant, dose-responsive inhibition of acetylcholin-esterase (the target molecule for methyl parathion-induced neurotoxicity) in brain or plasma, indicating that the compound was active. The following immunological parameters were evaluated: white blood cell counts and differentials, spleen and thymus weight and cellularity, splenic natural killer cell activity, nitrite production by peritoneal macrophages following activation in vitro, antibody response to sheep erythrocytes in vitro and in vivo, the cytotoxic T lymphocyte response to allogeneic tumor cells, and resistance to Streptococcus agalactiae and B16F10 melanoma cells. Methylparathion at 1 or 3 mg/kg/d significantly increased splenic natural killer cell activity. Nitrite production by macrophages was increased in mice treated with 1, 3, or 6 mg/kg/d. The antibody response to sheep erythrocytes in vitro was significantly suppressed, but the humoral response to sheep erythrocytes in vivo was not affected. The cytotoxic T-lymphocyte response to allogeneic tumor cells was not significantly affected. Host resistance was not significantly decreased. Although it remains possible that immunological parameters not tested here may be affected by methyl parathion, the present results do not suggest substantial immunotoxic potential for this compound.

UI	MeSH Term	Description	Entries
D007107	Immune System	The body's defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.	Immune Systems,System, Immune,Systems, Immune
D007306	Insecticides	Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.	Insecticide
D007694	Killer Cells, Natural	Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.	NK Cells,Natural Killer Cells,Cell, NK,Cell, Natural Killer,Cells, NK,Cells, Natural Killer,Killer Cell, Natural,NK Cell,Natural Killer Cell
D008743	Methyl Parathion	The methyl homolog of parathion. An effective, but highly toxic, organothiophosphate insecticide and cholinesterase inhibitor.	Metaphos,Parathion Methyl,Dalf,Metacid 50,Methylparathion,Vofatox,Wofatox
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005260	Female		Females
D000110	Acetylcholinesterase	An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.	Acetylcholine Hydrolase,Acetylthiocholinesterase,Hydrolase, Acetylcholine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013602	T-Lymphocytes, Cytotoxic	Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.	Cell-Mediated Lympholytic Cells,Cytotoxic T Cells,Cytotoxic T Lymphocyte,Cytotoxic T-Lymphocytes,TC1 Cell,TC1 Cells,TC2 Cell,TC2 Cells,Cell Mediated Lympholytic Cells,Cell, Cell-Mediated Lympholytic,Cell, TC1,Cell, TC2,Cell-Mediated Lympholytic Cell,Cytotoxic T Cell,Cytotoxic T Lymphocytes,Cytotoxic T-Lymphocyte,Lymphocyte, Cytotoxic T,Lympholytic Cell, Cell-Mediated,Lympholytic Cells, Cell-Mediated,T Cell, Cytotoxic,T Lymphocyte, Cytotoxic,T Lymphocytes, Cytotoxic,T-Lymphocyte, Cytotoxic
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus