Affiliations: Department of Pediatrics, Endocrine and Diabetes Unit,
University of British Columbia, Vancouver V5Z 4H4, BC, Canada | Department of Neurological Surgery, University of
California, San Francisco, CA, USA | Department of Obstetrics and Gynecology, University of
California, San Francisco, CA, USA
Note: [] MD, Clinical Professor and Head, British Columbia's Research
Institute, Room 170, 950 West 28th Avenue, Vancouver V5Z 4H4, Canada. Tel.: +1
604 875 2345 (ext 6597); Fax: +1 604 875 3231; E-mail: jchanoine@cw.bc.ca
Abstract: Glutathione peroxidase (GPx-1) is a selenoenzyme that metabolizes
H_2O_2, a source of potentially toxic
free radicals. Steroidogenesis is markedly inhibited by
H_2O_2 in vitro. {\it Objective:} to study the effects of selenium deficiency on GPx
activity and adrenal steroidogenesis in a novel adrenal cell line developed
using targeted tumorigenesis. {\it Methods:} AN4Rppc7 cells were grown for 7 days in serum-free
medium. 8-Br-cAMP-stimulated concentrations of steroid hormones were measured
by RIA. StAR (Steroid Acute Reactive Protein) mRNA was measured by Northern
blot. {\it Results:} selenium deficiency caused a 99% There was a 51%,
progesterone, corticosterone and aldosterone production,
respectivelyp<0.05 by ANOVA). StAR mRNA was not affected by
selenium. {\it Conclusions:} selenium deficiency causes a marked decrease in
GPx activity. Decreased steroid hormone production occurs for selenium
concentrations equal or lower than 5 nM. The absence of changes in StAR mRNA
content suggests that selenium deficiency does not affect cholesterol access to
the mitochondria.
