Journal Article

Increased Sensitivity to Testicular Toxicity of Transplacental Benzo[a]pyrene Exposure in Male Glutamate Cysteine Ligase Modifier Subunit Knockout (<i>Gclm−/−</i>) Mice

Brooke N. Nakamura, Isaac Mohar, Gregory W. Lawson, Mabel M. Cortés, Yvonne D. Hoang, Laura Ortiz, Reshma Patel, Bogdan A. Rau, Lisa A. McConnachie, Terrance J. Kavanagh and Ulrike Luderer

in Toxicological Sciences

Volume 126, issue 1, pages 227-241
Published in print March 2012 | ISSN: 1096-6080
Published online January 2012 | e-ISSN: 1096-0929 | DOI: http://dx.doi.org/10.1093/toxsci/kfs017
Increased Sensitivity to Testicular Toxicity of Transplacental Benzo[a]pyrene Exposure in Male Glutamate Cysteine Ligase Modifier Subunit Knockout (Gclm−/−) Mice

More Like This

Show all results sharing these subjects:

  • Medical Toxicology
  • Toxicology (Non-medical)

GO

Show Summary Details

Preview

Polycyclic aromatic hydrocarbons (PAHs), like benzo[a]pyrene (BaP), are ubiquitous environmental pollutants formed by the incomplete combustion of organic materials. The tripeptide glutathione (GSH) is a major antioxidant and is important in detoxification of PAH metabolites. Mice null for the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations. We investigated the effects of Gclm deletion alone on male fertility and spermatogenesis and its effect on the sensitivity of male embryos to the transplacental testicular toxicity of BaP. Gclm−/− males had dramatically decreased testicular and epididymal GCL enzymatic activity and total GSH concentrations compared with Gclm+/+ littermates. Ratios of reduced to oxidized GSH were significantly increased in Gclm−/− testes. GSH reductase enzymatic activity was increased in Gclm−/− epididymides. We observed no changes in fertility, testicular weights, testicular sperm head counts, or testicular histology and subtle changes in cauda epididymal sperm counts, motility, and morphology in Gclm−/− compared with Gclm+/+ males. Prenatal exposure to BaP from gestational day 7 to 16 was dose dependently associated with significantly decreased testicular and epididymal weights, testicular and epididymal sperm counts, and with vacuolated seminiferous tubules at 10 weeks of age. Gclm−/− males exposed prenatally to BaP had greater decreases in testicular weights, testicular sperm head counts, epididymal sperm counts, and epididymal sperm motility than Gclm+/+ littermates. These results show no effects of Gclm deletion alone on male fertility and testicular spermatogenesis and subtle epididymal effects but support increased sensitivity of Gclm−/− males to the transplacental testicular toxicity of BaP.

Keywords: glutathione; GCLM; PAH; benzo[a]pyrene; spermatogenesis; developmental toxicity

Journal Article.  8696 words.  Illustrated.

Subjects: Medical Toxicology ; Toxicology (Non-medical)

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.