Partial sequencing and tissue distribution of the canine isoforms of steroid 5alpha-reductase type I and type II.
BACKGROUND
The dog is regarded to be a valid model to test the effects of 5alpha-reductase inhibitors on prostatic growth. However, limited information is available on the characteristics or even existence of 5alpha-reductase isozymes in this species.


METHODS
Here, we set out to clone the cDNA of the dog isoforms of 5alpha-reductase type I and type II by a degenerate cloning strategy and to assess the tissue distribution of both transcripts and the enzymatic activity of the isozymes.


RESULTS
We identified two clones with homology to the human 5alpha-reductase isoforms type I and type II to be expressed in dog prostate. At the amino-acid level, these partial clones were found to exhibit a homology with their human counterparts of 83% and 88%, respectively. The expression levels of 5alpha-reductase mRNA were screened by RT-PCR in a number of dog tissues. No correlation was found between tissue mRNA expression and enzymatic 5alpha-reductase activities.


CONCLUSIONS
The present study describes the partial cloning of the dog 5alpha-reductase isozymes and their tissue distribution. These results provide additional data for the use of the dog as an animal model to investigate the role of 5alpha-reductase isozymes in steroid metabolism.
Span
P N
PN
Department of Chemical Endocrinology, University Medical Center Sint Radboud, Nijmegen, The Netherlands. p.span@ace.azn.nl
van Bokhoven
A
A
Smals
A G
AG
Sweep
C G
CG
Schalken
J A
JA
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D017931:DNA Primers / Q000737:chemistry; D004285:Dogs / Q000235:genetics* / Q000502:physiology; D004587:Electrophoresis, Agar Gel; D007527:Isoenzymes / Q000737:chemistry; D008297:Male; D008969:Molecular Sequence Data; D011467:Prostate / Q000201:enzymology* / Q000502:physiology; D012313:RNA / Q000737:chemistry / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012588:Scintillation Counting; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D007527:Isoenzymes; D012313:RNA; D004247:DNA; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase