Effects of Gestational and Lactational Fenvalerate Exposure on Immune and Reproductive Systems of Male Rats

Abstract

The aim of this study was to determine the consequent reproductive developmental and immunotoxic effects due to exposure to fenvalerate during pregnancy and lactation in male offspring of maternal-treated rats. Pregnant rats were treated daily by oral gavage with 40 or 80 mg/kg of fenvalerate or corn oil (vehicle, control), from d 12 of pregnancy to d 21 of lactation. Immune and reproductive developmental effects were assessed in male offspring at postnatal days (PND) 40 (peripuberty), 60 (postpuberty), and 90 (sexual maturity). Treatment with the higher dose (80 mg/kg) resulted in convulsive behavior, hyperexcitability, and mortality in 45% of the dams. Fenvalerate was detected in the fetus due to placental transfer, as well as in pups due to breast-milk ingestion, persisting in male offspring until PND 40 even though pesticide treatment was terminated on PND 20. However, fenvalerate did not produce marked alterations in age of testicular descent to the scrotum and prepucial separation, parameters indicative of puberty initiation. In contrast, at puberty, there was a reduction in testicular weight and sperm production in male offspring of maternal-treated rats. At adulthood, the sperm counts and fertility did not differ between control and treated groups. Testosterone levels were not changed at any time during reproductive development. Similarly, no apparent exposure-related effects were detected in the histological structures of the lymphohematopoietic system. Data indicate that fenvalerate, in this experimental model, interfered with initial development of the male reproductive system, but that these effects on sperm production or fertility did not persist into adulthood. There was no apparent evidence that fenvalerate altered testosterone levels or produced a disruption in male endocrine functions.

Subacute toxicity assessment of diflubenzuron, an insect growth regulator, in adult male rats

“…Several studies have been conducted to evaluate the reproductive toxicity of pesticides in mammals. Some pesticides that induce reproductive toxicity are: dimethoate (Verma and Mohanty, ), fenvalerate (Arena et al, ; Nassr et al, ), dichlorvos (Diricana and Kalender, ), propetamphos (Ismail and Al‐Taher, ), glyphosate (Romano et al, ), among others. Reproductive toxicity studies should be conducted as part of the toxicity evaluation of any compound, which complements the systemic toxicity tests (Dalsenter et al, ).…”

Maternal exposure to butyl paraben impairs testicular structure and sperm quality on male rats

“…Three nonconsecutive sections (5 μm thick) per animal, separated by 100 μm distance, were obtained, mounted on glass slides, and stained with H&E. The histological evaluation of organs was accomplished quantitatively for testis and qualitatively for epididymis under a light microscope following specific guidelines for toxicological studies (Foley, ). Nuclei of Sertoli cells were counted in 20 cross‐sections of seminiferous tubules per rat, under a light microscope, at 400× magnification (Nassr et al, , with modifications).…”

Within- and Between-Child Variation in Repeated Urinary Pesticide Metabolite Measurements over a 1-Year Period

“…After the 2001 U.S. EPA voluntary phaseout of residential OP use, pyrethroids have become the principal pesticide class used for indoor pest control (Sudakin 2006), creating opportunities for dermal, inhalation, and incidental ingestion exposures (Agency for Toxic Substances and Disease Registry 2003). In addition to acute poisonings, epidemiological studies have reported evidence of neurotoxic and developmental effects from OP exposures (Bouchard et al 2010; Harley et al 2011; Rauh et al 2011) and evidence of reproductive toxicity (Meeker et al 2008; Nassr et al 2010) and endocrine disruption (Han et al 2008; Meeker et al 2009) associated with pyrethroid exposures. In addition, the U.S. EPA has listed permethrin, a widely used pyrethroid for both agricultural and residential insect control, as “likely to be carcinogenic to humans” (U.S.…”