squeegee
Banned
- Reaction score
- 132
Toxicol Appl Pharmacol. 2004 Sep 15;199(3):316-31.
Mechanisms that regulate production of reactive oxygen species by cytochrome P450.
Zangar RC, Davydov DR, Verma S.
Source
Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Abstract
Mammalian cytochromes P450 (P450) are a family of heme-thiolate enzymes involved in the oxidative metabolism of a variety of endogenous and exogenous lipophilic compounds. Poor coupling of the P450 catalytic cycle results in continuous production of reactive oxygen species (ROS), which affects signaling pathways and other cellular functions. P450 generation of ROS is tightly controlled by regulation of gene transcription as well as by modulation of interactions between protein constituents of the monooxygenase that affects its activity, coupling, and stability. Malfunction of these mechanisms may result in a burst of ROS production, which can cause lipid peroxidation and oxidative stress. In turn, oxidative stress downregulates P450 levels by a variety of feedback mechanisms. This review provides an overview of recent advances in our understanding of these feedback mechanisms that serve to limit P450 production of ROS. Some of the more likely physiological and cellular effects of P450 generation of ROS are also discussed.
- - - Updated - - -
Steroidogenic Isoenzymes in
Human Hair and Their Potential Role
in Androgenetic Alopecia
Androgenetic alopecia (Androgenetic Alopecia) is the most common typeof hair loss. The relatively strong concordance of the
degree of baldness in fathers and sons is not consistent
with a simple Mendelian trait, and a polygenic basis is
considered to be most likely. So far, the predisposing
genes for Androgenetic Alopecia are unknown and we do not understand
the molecular steps involved in androgen-dependent
beard growth versus androgen-dependent hair loss, but
Androgenetic Alopecia can be defined as a dihydrotestosterone (DHT)-
dependent process with continuous miniaturization of
sensitive hair follicles. The type 2 5
·
-reductase plays a
central role by the intrafollicular conversion of testoster-
one to DHT. However, due to the increasing knowledge
in this field, we now know that there are many more ste-
roidogenic enzymes involved in the onset and develop-
ment of Androgenetic Alopecia, and this article shall provide a critical over-
view of recent discoveries
http://www.cunliffe-awards.de/pdfs/publikation_hofmann.pdf
Mechanisms that regulate production of reactive oxygen species by cytochrome P450.
Zangar RC, Davydov DR, Verma S.
Source
Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Abstract
Mammalian cytochromes P450 (P450) are a family of heme-thiolate enzymes involved in the oxidative metabolism of a variety of endogenous and exogenous lipophilic compounds. Poor coupling of the P450 catalytic cycle results in continuous production of reactive oxygen species (ROS), which affects signaling pathways and other cellular functions. P450 generation of ROS is tightly controlled by regulation of gene transcription as well as by modulation of interactions between protein constituents of the monooxygenase that affects its activity, coupling, and stability. Malfunction of these mechanisms may result in a burst of ROS production, which can cause lipid peroxidation and oxidative stress. In turn, oxidative stress downregulates P450 levels by a variety of feedback mechanisms. This review provides an overview of recent advances in our understanding of these feedback mechanisms that serve to limit P450 production of ROS. Some of the more likely physiological and cellular effects of P450 generation of ROS are also discussed.
- - - Updated - - -
Steroidogenic Isoenzymes in
Human Hair and Their Potential Role
in Androgenetic Alopecia
Androgenetic alopecia (Androgenetic Alopecia) is the most common typeof hair loss. The relatively strong concordance of the
degree of baldness in fathers and sons is not consistent
with a simple Mendelian trait, and a polygenic basis is
considered to be most likely. So far, the predisposing
genes for Androgenetic Alopecia are unknown and we do not understand
the molecular steps involved in androgen-dependent
beard growth versus androgen-dependent hair loss, but
Androgenetic Alopecia can be defined as a dihydrotestosterone (DHT)-
dependent process with continuous miniaturization of
sensitive hair follicles. The type 2 5
·
-reductase plays a
central role by the intrafollicular conversion of testoster-
one to DHT. However, due to the increasing knowledge
in this field, we now know that there are many more ste-
roidogenic enzymes involved in the onset and develop-
ment of Androgenetic Alopecia, and this article shall provide a critical over-
view of recent discoveries
http://www.cunliffe-awards.de/pdfs/publikation_hofmann.pdf