scholarly journals Neurosteroid metabolism. 7α-Hydroxylation of dehydroepiandrosterone and pregnenolone by rat brain microsomes

1992 ◽  
Vol 288 (3) ◽  
pp. 959-964 ◽  
Author(s):  
Y Akwa ◽  
R F Morfin ◽  
P Robel ◽  
E E Baulieu
Keyword(s):  
Rat Brain ◽  
Microsomal Protein ◽  
Optimal Conditions ◽  
Hydroxylated Metabolites ◽  
Enzymic Reaction ◽  
Polar Metabolites ◽  
Brain Microsomes ◽  
Prepubertal Rats ◽  
Derivatives Of

Two ‘neurosteroids’, dehydroepiandrosterone (DHEA) and pregnenolone (PREG), are converted by rat brain microsomes into polar metabolites, identified as the respective 7 alpha-hydroxylated (7 alpha-OH) derivatives by the ‘twin ion’ technique of g.l.c.-m.s. with deuterated substrates. The enzymic reaction requires NADPH and is stimulated 2-4-fold by EDTA. Under optimal conditions (pH 7.4, 0.5 mM-NADPH, 1 mM-EDTA), the Km values for DHEA and PREG are 13.8 and 4.4 microM respectively, and the Vmax. values are 322 and 38.8 pmol/min per mg of microsomal protein respectively. Trace amounts of putative 7 beta-OH derivatives of DHEA and PREG are detected. Oestradiol, at a pharmacological concentration of 5 microM, inhibits DHEA and PREG 7 alpha-hydroxylation. Formation of 7 alpha-hydroxylated metabolites is low in prepubertal rats and increases 5-fold in adults. Derivatives of PREG and DHEA, such as PREG sulphate, DHEA sulphate, progesterone and 3 alpha-hydroxy-5 alpha-pregnan-20-one, are known to be neuroactive. Therefore the quantitatively important metabolism to 7 alpha-OH compounds may contribute to the control of neurosteroid activity in brain.

Microsomal Protein Mediates a pH-Dependent Fusion of Liposomes to Rat Brain Microsomes

1990 ◽  
Vol 9 (4) ◽  
pp. 253-261 ◽  
Author(s):  
Roberto Pistolesi ◽  
Lanfranco Corazzi ◽  
Giuseppe Arienti
Keyword(s):  
Rat Brain ◽  
Microsomal Protein ◽  
Brain Microsomes ◽  
Ph Dependent

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

Ethanol and inositol 1,4,5-trisphosphate mobilize calcium from rat brain microsomes

Alcohol ◽  
1989 ◽  
Vol 6 (6) ◽  
pp. 431-436 ◽  
Author(s):  
Tina Machu ◽  
John J. Woodward ◽  
Steven W. Leslie
Keyword(s):  
Rat Brain ◽  
Inositol 1,4,5 Trisphosphate ◽  
Brain Microsomes

ACYLATION OF LYSOPHOSPHATIDYLSERINE BY RAT BRAIN MICROSOMES

1979 ◽  
Vol 33 (5) ◽  
pp. 1061-1066 ◽  
Author(s):  
O. A. James ◽  
G. MacDonald ◽  
W. Thompson
Keyword(s):  
Rat Brain ◽  
Brain Microsomes

CMP-Dependent Degradation of Platelet-Activating Factor (PAF) by Rat Brain Microsomes

1997 ◽  
pp. 1029-1034
Author(s):  
Ermelinda Francescangeli ◽  
Serena Porcellati ◽  
Gianfrancesco Goracci
Keyword(s):  
Rat Brain ◽  
Platelet Activating Factor ◽  
Brain Microsomes

scholarly journals Eco-friendly plant growth and development regulators on the basis of derivatives 1,2,4-triazines

2021 ◽  
Vol 36 ◽  
pp. 02003
Author(s):  
E.A. Builova ◽  
A.K. Mazitova ◽  
G.K. Aminova ◽  
I.I. Zaripov ◽  
A.H. Alibakova
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Target Product ◽  
Optimal Conditions ◽  
Laboratory Studies ◽  
Plant Growth And Development ◽  
Effect Of Solvents ◽  
Etiolated Seedlings ◽  
Working Solution ◽  
Derivatives Of

The article considers the application of plant growth and development regulators, in particular, derivatives of asymmetric triazines. A method for obtaining hexahydro-1,2,4-triazinone-3 is given. Optimal conditions for the reaction of 1,2-dichloroethane with semicarbazide are determined: reaction time, process temperature, and the effect of solvents on the yield of the target product. The results of laboratory and vegetation tests of 1,2,4-triazinone-3 for biological activity are presented. Laboratory studies were carried out on seeds of wheat, cucumbers, radish and vetch, which were laid out in Petri dishes and poured with a working solution, the concentration of the drug is 1, 10 mg/l. Two days later, the length and weight of etiolated seedlings were determined. Vegetation tests were carried out on seeds of barley, wheat and rye with a concentration of 10 mg/l. After two weeks, the length and weight of the plants were measured.

Comparing induced and non-induced rat brain microsomes from xenotech

2018 ◽  
Vol 33 (1) ◽  
pp. S77
Author(s):  
Ying Liu ◽  
Jiansheng Huang ◽  
Kevin Westland ◽  
Aaron Hilgedick ◽  
Stephanie Helmstetter ◽  
...  
Keyword(s):  
Rat Brain ◽  
Brain Microsomes

Formation of α-Methyldopamine (‘Catecholamphetamine’) from p-Hydroxyamphetamine by Rat Brain Microsomes

Pharmacology ◽  
1979 ◽  
Vol 19 (5) ◽  
pp. 256-260 ◽  
Author(s):  
Andrew R. Hoffman ◽  
Rama Sastry ◽  
Julius Axelrod
Keyword(s):  
Rat Brain ◽  
Brain Microsomes
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