PMID- 12701738
OWN - NLM
STAT- MEDLINE
DCOM- 20030722
LR  - 20190716
IS  - 0001-6489 (Print)
IS  - 0001-6489 (Linking)
VI  - 123
IP  - 2
DP  - 2003 Jan
TI  - Steroidogenic enzyme expression in the rat cochlea.
PG  - 187-91
AB  - OBJECTIVE: Steroid hormones, and particularly mineralocorticoids, are candidates 
      for controlling the homeostasis of endolymph as steroid receptors are widely 
      expressed in the cochlea. In contrast, experiments on adrenalectomized animals 
      have shown that an absence of steroids had little effect on the ionic composition 
      of endolymph and hearing ability. We thus hypothesized that local production of 
      steroids in the inner ear may regulate cochlear fluid exchanges. RESULTS: Using 
      reverse transcription-polymerase chain reaction techniques, we showed that 
      transcripts encoding the P450 side-chain cleavage, the 3beta hydroxysteroid 
      dehydrogenase (3beta HSD) and the 17alpha hydroxylase (P450 C17) were expressed 
      in the lateral wall, organ of Corti and modiolus. The mRNA encoding aldosterone 
      synthase was expressed in the modiolus and lateral wall while the P450 11beta1 
      hydroxylase was not detected at all in any of these tissues. In situ 
      hybridization experiments on cochlear sections confirmed that the 3beta HSD 
      transcripts were expressed in the spiral ligament and modiolus and possibly in 
      the hair cells of the organ of Corti. However, it was not possible to detect P450 
      C17 transcripts. Immunohistochemistry performed with an antibody raised against 
      the various 3beta HSD isoforms confirmed the localization found using in situ 
      hybridization. CONCLUSIONS: These results suggest that enzymes of the steroid 
      pathway leading to mineralocorticoids and sex steroid hormones, but not 
      glucocorticoids, may be expressed in the rat cochlea. This work is in line with 
      the recent description of local production of steroid hormones in the brain 
      (neurosteroids), heart and skin. In the cochlea, the local production of mineralo 
      and sex steroids could account for a paracrine role and could induce specific 
      gene expression through steroid receptors or act via a non-genomic mechanism on 
      membrane receptors or ionic exchangers. Experiments aimed at demonstrating 
      enzymatic activities within cochlea tissues are in progress.
FAU - Lecain, Eric
AU  - Lecain E
AD  - LNRS, UMR 7060, Faculte Lariboisiere, Hopital Lariboisiere, Paris, France.
FAU - Yang, Ting-Hua
AU  - Yang TH
FAU - Tran Ba Huy, Patrice
AU  - Tran Ba Huy P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Acta Otolaryngol
JT  - Acta oto-laryngologica
JID - 0370354
RN  - 0 (RNA, Messenger)
RN  - 0 (Steroids)
RN  - EC 1.1.- (3-Hydroxysteroid Dehydrogenases)
RN  - EC 1.14.14.19 (Steroid 17-alpha-Hydroxylase)
RN  - EC 1.14.15.6 (Cholesterol Side-Chain Cleavage Enzyme)
SB  - IM
MH  - 3-Hydroxysteroid Dehydrogenases/*metabolism
MH  - Animals
MH  - Cholesterol Side-Chain Cleavage Enzyme/*metabolism
MH  - Cochlea/*enzymology/pathology
MH  - Immunohistochemistry
MH  - In Situ Hybridization
MH  - Models, Animal
MH  - Organ Culture Techniques
MH  - RNA, Messenger/analysis
MH  - Rats
MH  - Rats, Inbred LEC
MH  - *Reverse Transcriptase Polymerase Chain Reaction
MH  - Sensitivity and Specificity
MH  - Steroid 17-alpha-Hydroxylase/*metabolism
MH  - Steroids/metabolism
EDAT- 2003/04/19 05:00
MHDA- 2003/07/23 05:00
CRDT- 2003/04/19 05:00
PHST- 2003/04/19 05:00 [pubmed]
PHST- 2003/07/23 05:00 [medline]
PHST- 2003/04/19 05:00 [entrez]
AID - 10.1080/0036554021000028106 [doi]
PST - ppublish
SO  - Acta Otolaryngol. 2003 Jan;123(2):187-91. doi: 10.1080/0036554021000028106.