Immunotoxicity study of repeated small doses of dimethoate and methylparathion administered to rats over three generations

• Published in: Human & experimental toxicology Vol. 14; no. 11; pp. 879 - 883
• Main Authors: Institóris, L., Siroki, Olga, Dési, I.
• Format: Journal Article
• Language: English
• Published: Thousand Oaks, CA SAGE Publications 01.11.1995; Arnold
• Subjects: Animals; Biological and medical sciences; Body Weight - drug effects; Bone Marrow - drug effects; Cholinesterase Inhibitors - administration & dosage; Cholinesterase Inhibitors - toxicity; Dimethoate - administration & dosage; Dimethoate - toxicity; Dose-Response Relationship, Drug; Erythrocytes - drug effects; Female; Hematocrit; Immune System - drug effects; Insecticides - administration & dosage; Insecticides - toxicity; Lethal Dose 50; Leukocytes - drug effects; Litter Size - drug effects; Liver - drug effects; Male; Medical sciences; Methyl Parathion - administration & dosage; Methyl Parathion - toxicity; Organ Size - drug effects; Pesticides, fertilizers and other agrochemicals toxicology; Rats; Rats, Wistar; Specific Pathogen-Free Organisms; Spleen - cytology; Spleen - drug effects; Thymus Gland - drug effects; Toxicology; Weight Gain - drug effects; methylparathion; immunotoxicity; dimethoate; three generations; rat; Immunopathology; Insecticide; Rat; Toxicity; Low dose; Rodentia; Pesticides; Multigeneration study; Multiple dose; Vertebrata; Chronic; Mammalia; Animal; Organophosphorus compounds; Dimethoate; Immune system
• ISSN: 0960-3271; 1477-0903
• DOI: 10.1177/096032719501401104

Immunotoxic effects of chronic, equitoxic doses (1/50, 1/75, and 1/100 LD50) of two organophosphorus pesticides dimethoate (DM) and methylparathion (MPT) (14.1, 9.39, and 7.04 mg kg-1 DM; and 0.436, 0.291, and 0.218 mg kg-1 MPT) were investigated in a three generation study in out- bred Wistar rats. Treatment of the first generation (G1) with these doses began in animals 4 weeks of age; the parental males were dosed until separation of females, and after mating the females were treated until separation of their G2 offspring (at the age of 4 weeks), and the G3 generation was produced in the same way from treated parental G2 animals. Selected 4 week old males from each generation were also treated with DM and MPT for 4 weeks (experimental groups) before determination of certain conventional toxicological (body weight gain, birth weight and number, organ weights), haematological (absolute and differential WBC, RBC, Ht, MCV, nucleated cell content of femoral bone marrow), and immune func tion parameters (IgM-PFC number of spleen, DTH reac tion). Effects of both substances on immunological variables were detectable at the 1/75 LD50 dose level, but different parameters were affected in the three consecutive genera tions.