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Cations inhibit specifically type I 5 alpha-reductase found in human skin
Y Sugimoto1, I López-Solache, F Labrie
1Medical Research Council Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
The Journal of Investigative Dermatology
|May 1, 1995
Summary
Cations differentially affect steroid 5 alpha-reductase types. Type I is strongly inhibited by cadmium, copper, and zinc, while type II is primarily affected by copper, suggesting specific cation control.
Area of Science:
- Biochemistry
- Molecular Biology
- Endocrinology
Background:
- Steroid 5 alpha-reductase enzymes are crucial for converting testosterone to dihydrotestosterone.
- Human 5 alpha-reductase exists in two main types: Type I, prevalent in skin, and Type II, specific to the prostate.
- Understanding differential cation effects on these enzyme types is important for targeted therapeutic strategies.
Purpose of the Study:
- To investigate the impact of various cations on the activity of human Type I and Type II 5 alpha-reductase.
- To determine if specific cations can differentially modulate the activity of the two 5 alpha-reductase isozymes.
Main Methods:
- Expression vectors for human Type I and Type II 5 alpha-reductase were created.
- These vectors were transfected into SW-13 cells, a cell line with low endogenous 5 alpha-reductase activity.
- The expressed enzymes were analyzed for sensitivity to a panel of cations (Li, Ca, Cd, Cu, Mg, Mn, Ni, Zn, Fe).
Main Results:
- Type I 5 alpha-reductase showed strong inhibition by cadmium (Cd), copper (Cu), and zinc (Zn), with IC50 values of 0.9, 1.9, and 2.0 µM, respectively.
- Moderate inhibition of Type I was observed with nickel (Ni) and iron (Fe).
- Type II 5 alpha-reductase activity was selectively inhibited by copper (Cu) with an IC50 of 19.2 µM, showing less sensitivity to other tested cations.
Conclusions:
- Cations can specifically modulate the activity of different 5 alpha-reductase isozymes.
- Type I 5 alpha-reductase is more susceptible to inhibition by a broader range of cations compared to Type II.
- These findings highlight the potential for cation-based strategies to selectively control 5 alpha-reductase activity in specific tissues like the skin.