Alterations of T cell distribution and functions in prenatally cypermethrin-exposed rats: possible involvement of catecholamines

Toxicology. 1999 Nov 15;138(3):175-87. doi: 10.1016/s0300-483x(99)00103-1.


The synthetic pyrethroid insecticide, cypermethrin (50 mg/Kg) was given during gestation to pregnant rats by gavage in corn oil. Prenatal cypermethrin-exposure induces a marked and long-lasting increase of adrenaline (A) and noradrenaline (NA) plasma concentrations. The enhancement of plasma catecholamine levels was accompanied by a marked increase of CD5+, CD4+, and CD8+ total T cell numbers in the peripheral blood, while in the spleen a reduction of all T cell subsets was observed. In addition, peripheral blood lymphocytes (PBL) from rats prenatally exposed to cypermethrin showed an enhanced capability to proliferate in response to different doses of Concanavalin A (ConA), or human recombinant interleukin-2 (hrIL-2), whereas an impaired proliferative response was observed in the spleen. The percent increase of NA, but not A plasma concentrations paralleles the immunomodulatory effects induced by cypermethrin neonatal exposure on T cell distribution and mitogen-induced proliferation in the peripheral blood and spleen. Collectively, our results suggest that the changes in mitogen-induced proliferative responses in the peripheral blood and spleen of prenatally cypermethrin-exposed rats may be attributable to pesticide-induced catecholamine release, which causes an increased output of CD5+, CD4+, and CD8+ T cells from the spleen to the peripheral blood, and a consequent lymphocytosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / toxicity*
  • Animals
  • Animals, Newborn
  • Catecholamines / blood*
  • Cell Division / drug effects
  • Epinephrine / metabolism
  • Female
  • Flow Cytometry
  • Fluorescent Antibody Technique, Direct
  • Insecticides / toxicity*
  • Lymphocyte Count / drug effects
  • Male
  • Mitogens / pharmacology
  • Norepinephrine / metabolism
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Pyrethrins / toxicity*
  • Rats
  • Rats, Wistar
  • Spleen / cytology
  • Spleen / drug effects
  • T-Lymphocyte Subsets / drug effects
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / immunology


  • Adjuvants, Immunologic
  • Catecholamines
  • Insecticides
  • Mitogens
  • Pyrethrins
  • cypermethrin
  • Norepinephrine
  • Epinephrine