title: Expression of aryl hydrocarbon receptor and aryl hydrocarbon receptor nuclear translocator messenger ribonucleic acids and proteins in rat and human testis.
abstract: Dioxins, e.g. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), use the aryl hydrocarbon receptor (AHR)/aryl hydrocarbon receptor nuclear translocator (ARNT) receptor complex to mediate their toxic actions. In addition to interaction with environmental pollutants, several transcription factors, steroid receptors, and growth factors are capable interacting with the AHR/ARNT complex, which suggests a constitutive role for the receptor complex. The testis has been reported to be among the most sensitive organs to TCDD exposure. Our experiments revealed a complex distribution of AHR and ARNT mRNAs and proteins in rat and human testis. AHR and ARNT immunoreactivities could be detected in the nuclei of interstitial and tubular cells. The incubation of seminiferous tubules in a serum-free culture medium resulted in up-regulation of AHR mRNA, which could be depressed by adding FSH to the culture medium. Furthermore, the incubation of tubular segments with a solution of 1 or 100 nM TCDD resulted in a 2- to 3-fold increase in apoptotic cells. Thus, up-regulation of AHR in cultured tubular segments and consecutive depression by FSH suggest a role for AHR in controlled cell death during spermatogenesis. We suggest that AHR and ARNT mediate effects by direct action on testicular cells in the rat and human testis.
authors.affiliation: Department of Developmental Biology, Tampere University, FIN-33014 Tampere, Finland.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Schultz
authors.forename: Janne
authors.initials: J
authors.lastname: Suominen
authors.forename: Tanja
authors.initials: T
authors.lastname: Värre
authors.forename: Harri
authors.initials: H
authors.lastname: Hakovirta
authors.forename: Martti
authors.initials: M
authors.lastname: Parvinen
authors.forename: Jorma
authors.initials: J
authors.lastname: Toppari
authors.forename: Markku
authors.initials: M
authors.lastname: Pelto-Huikko
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D015152:Blotting, Northern; D002467:Cell Nucleus / Q000737:chemistry; D016895:Culture Media, Serum-Free; D046508:Culture Techniques; D004268:DNA-Binding Proteins; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018336:Receptors, Aryl Hydrocarbon / Q000032:analysis* / Q000235:genetics*; D012671:Seminiferous Tubules / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000737:chemistry*; D014018:Tissue Distribution; D014157:Transcription Factors / Q000032:analysis* / Q000235:genetics*
chemical_list: C497396:ARNT protein, human; C497398:ARNT protein, rat; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D014157:Transcription Factors; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D005640:Follicle Stimulating Hormone