Regional distribution of cytosolic and particulate 5α-dihydroprogesterone 3α-hydroxysteroid oxidoreductases in female rat brain

doi:10.1016/S0960-0760(96)00195-1

The Journal of Steroid Biochemistry and Molecular Biology

Volume 60, Issues 5–6, March 1997, Pages 311-318

https://doi.org/10.1016/S0960-0760(96)00195-1 Get rights and content

Abstract

Numerous studies have indicated that progesterone metabolites, particularly 3α,5α-tetrahydroprogesterone, can potently influence multiple brain functions, e.g. they have the capacity to mediate gonadotropin regulation and various anticonvulsive, anesthetic and anxiolytic effects. These circulating progesterone metabolites are likely to represent only a fraction of the bioavailable pool of these steroids in that the central nervous system (CNS) also possesses enzymes that can synthesize these metabolites in situ. Therefore, because the ability of the CNS to produce these neuroactive progestins is an important consideration when assessing overall progestin function and metabolism, we measured the major progesterone metabolizing enzyme activities, namely the cytosolic NADPH and particulate NADH 5α-dihydroprogesterone 3α-hydroxysteroid oxidoreductase (3α-HSOR) and progesterone 5α-reductase activities in nine brain regions from random cycling and ovariectomized rats. These assays entailed the use of reverse isotopic dilution analysis and revealed that all three enzymic activities were present in each of the brain regions examined, but that these regions displayed differential patterns with regard to their levels of cytosolic and particulate 3α-HSOR activity. The cytosolic 3α-HSOR activity was highest in the olfactory bulb/tubercle and colliculi regions which were greater than levels in the hypothalamus/preoptic area and cerebellum which were greater than levels in the amygdala/striatum and hippocampus/dentate gyrus. Midbrain/thalamus, cerebral cortex and pons/medulla were different only from the olfactory bulb/tubercle and colliculi regions. The particulate 3α-HSOR activity was highest in the olfactory bulb/tubercle region followed by colliculi, hippocampus/dentate gyrus and pons/medulla which were greater than levels in the hypothalamus/preoptic area, cerebellum and amygdala/striatum. Cerebral cortex and midbrain/thalamus were different only from the olfactory bulb/tubercle area. The highest levels of 5α-reductase activity were found in the pons/medulla region followed by the colliculi, midbrain/thalamus, cerebellum and olfactory bulb/tubercle which were greater than levels in the amygdala/striatum, hippocampus/dentate gyrus, hypothalamus/preoptic area and cerebral cortex. It is interesting to note that although 5α-reductase may control, at least in part, substrate levels for the 3α-HSORs, the distribution of 5α-reductase activity in these nine brain regions did not correlate with 3α-HSOR levels. The differences in the levels of activity of these three enzymes in various brain regions suggests a role in maintaining a differential balance of the neuroactive steroid, 3α,5α-tetrahydroprogesterone, and its precursor, 5α-dihydroprogesterone, in various regions of the CNS.

References (27)

P. Duchamp-Viret et al.
GABAergic control of odor-induced activity in the frog olfactory bulb: electrophysiological study with picrotoxin and bicuculline
Neuroscience
(1993)
R.R. Matsumoto
GABA receptors: are cellular differences reflected in function
Brain Res. Rev.
(1989)
S.J. Bertics et al.
Distribution and ovarian control of progestin-metabolizing enzymes in various rat hypothalamic regions
J. Steroid Biochem.
(1987)
K.-C. Cheng et al.
Distribution and ontogeny of 3α-hydroxysteroid dehydrogenase in the rat brain
J. Steroid Biochem. Molec. Biol.
(1994)
J.M. Palacios et al.
High affinity GABA receptors — autoradiographic localization
Brain Res.
(1981)
J.S. Campbell et al.
Characterization of the purified pituitary cytosolic NADPH:5α-dihydroprogesterone 3α-hydroxysteroid oxidoreductase
J. Steroid Biochem. Molec. Biol.
(1990)
H.J. Karavolas et al.
Barbiturates modulate the activity of the pituitary 3α-hydroxysteroid oxidoreductases and inhibit their production of 3α,5α-tetrahydroprogesterone
J. Steroid Biochem. Molec. Biol.
(1993)
J.E. Krause et al.
Subcellular location of hypothalamic progesterone metabolizing enzymes and evidence for distinct NADH- and NADPH-linked 3α-hydroxysteroid oxidoreductase activities
J. Steroid Biochem.
(1980)
M.M. Bradford
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding
Analyt. Biochem.
(1976)
T.M. Penning et al.
Purification and properties of 3α-hydroxysteroid dehydrogenase from rat brain cytosol
J. Biol. Chem.
(1985)

P.J. Bertics et al.

Partial characterization of the microsomal and solubilized hypothamalic progesterone 5α-reductase

J. Steroid Biochem.

(1984)

S.M. Paul et al.

Neuroactive steroids

FASEB J.

(1992)

M.D. Majewska

Neurosteroids: endogenous bimodal modulators of the GABA_A receptor

Mechanism of action and physiological significance

Progr. Neurobiol.

(1992)

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Regional distribution of cytosolic and particulate 5α-dihydroprogesterone 3α-hydroxysteroid oxidoreductases in female rat brain

Abstract

Neuroscience

Brain Res. Rev.

J. Steroid Biochem.

J. Steroid Biochem. Molec. Biol.

Brain Res.

J. Steroid Biochem. Molec. Biol.

J. Steroid Biochem. Molec. Biol.

J. Steroid Biochem.

Analyt. Biochem.

J. Biol. Chem.

J. Steroid Biochem.

Neuroactive steroids

FASEB J.

Neurosteroids: endogenous bimodal modulators of the GABAA receptor

Mechanism of action and physiological significance

Progr. Neurobiol.

Neurosteroids: endogenous bimodal modulators of the GABA_A receptor