Testosterone 5α-Reductase in Rat Brain

We describe a simple procedure for the microassay of testosterone 5α-reductase in homogenates of rat brain. This enzyme converts testosterone to dihydrotestosterone. We have used this assay to characterize the enzymatic activity and to map its distribution. The apparent Km is 4.1 × 10⁻⁶ M and the Vm...

Full description

Saved in:
Bibliographic Details
Published inJournal of neurochemistry Vol. 40; no. 5; pp. 1460 - 1464
Main Authors Krieger, Neil R, Scott, Robert G, Jurman, Mark E
Format Journal Article
LanguageEnglish
Published England Blackwell Publishing Ltd 01.05.1983
Subjects
3-Oxo-5-alpha-Steroid 4-Dehydrogenase - metabolism
Animals
Brain - enzymology
Edetic Acid - pharmacology
Freezing
Hydrogen-Ion Concentration
Kinetics
Male
Oxidoreductases - metabolism
Rats
Rats, Inbred Strains
Online AccessGet more information

Cover

More Information
Summary:We describe a simple procedure for the microassay of testosterone 5α-reductase in homogenates of rat brain. This enzyme converts testosterone to dihydrotestosterone. We have used this assay to characterize the enzymatic activity and to map its distribution. The apparent Km is 4.1 × 10⁻⁶ M and the Vmax is 85.6 pmol/mg protein/h. The pH optimum is broad and extends from pH 6.0 to 8.0. For the brain regions surveyed, testosterone 5α-reductase activity varied over a 10-fold range. The highest activities were observed in homogenates of the midbrain and pons (37-39 pmol/mg protein/h). The lowest were seen in homogenates of the thalamus, caudate nucleus, frontal cortex, hippocampus, hypothalamus, olfactory tubercle, and preoptic area (3-7 pmol/mg protein/h).
Bibliography:http://dx.doi.org/10.1111/j.1471-4159.1983.tb13591.x
ISSN:0022-3042
1471-4159
DOI:10.1111/j.1471-4159.1983.tb13591.x