IN VITRO METABOLISM OF STEROID HORMONES BY CHICKEN BRAIN

1974 ◽  
Vol 75 (2) ◽  
pp. 410-416 ◽  
Author(s):  
Takao Nakamura ◽  
Yuichi Tanabe
Keyword(s):  
Steroid Hormones ◽  
Brain Homogenate ◽  
Hydroxysteroid Dehydrogenase ◽  
In Vitro Metabolism ◽  
Differential Centrifugation ◽  
White Leghorn ◽  
Chicken Brain ◽  
The Brain

ABSTRACT The brains of 14-month-old White Leghorn cocks were homogenized, fractionated by differential centrifugation, and used as enzymatic materials. When [4-14C]pregnenolone was incubated with the brain homogenate, the substrate was recovered without conversion. After incubation of [4-14C] progesterone with the brain homogenate, it was converted to 5α-pregnanedione and 3α-hydroxy-5α-pregnan-20-one. When [4-14C]17α-hydroxyprogesterone was incubated with the brain homogenate, it was metabolized to androstenedione, 3α, 17α-dihydroxy-5α-pregnan-20-one and 17α,20α-dihydroxy-4-pregnen-3-one. [4-14C] Androstenedione was metabolized to 5α-androstanedione, testosterone, androsterone, epiandrosterone and 5α-androstanediol; and [4-14C]testosterone was metabolized to androstenedione, 5β-dihydrotestosterone and 5β-androstanediol in the chicken brain. The enzymatic pattern in the brain of cocks was characterized by high activities of the 17β-hydroxysteroid dehydrogenase. Δ4-5β- and Δ5-5β-hydrogenase which acted on both C19- and C21-steroids, but was lacking in Δ5-3β-hydroxysteroid dehydrogenase associated with the Δ5a-Δ4isomerase, and 17α-hydroxylase.

scholarly journals A study on Dowager Cixi’s Yanling-Yishou-Dan of Qing Dynasty in a Japanese laboratory of biochemistry and molecular biology in 1990s: An attempt for TCM modernization

2021 ◽  
pp. 1-21
Author(s):  
Jiankang Liu
Keyword(s):  
Qing Dynasty ◽  
Brain Homogenate ◽  
Modern Technology ◽  
Toxicity Tests ◽  
Brain Functions ◽  
Great Progress ◽  
Theoretical Evidence ◽  
The Brain

Traditional Chinese Medicine (TCM) modernization has been proposed for many years, but the progress is still slow due to both ideological and technical obstacles. When I went to Japan in 1989, I found Japan has made a great progress on TCM by using modern technology. Therefore, I have studied a fine extract prepared from medicinal herbs (renamed Yi-Zhi-Yi-Shou, YZYS), a prescription of Dowager Cixi’s Yanling-Yishou-Dan of Qing Dynasty, with the current drug investigation strategies. I examined its antioxidant activity both in vitro and in vivo. The in-vitro studies found that YZYS possesses strong antioxidant capacity, such as scavenging various kinds of free radicals, and inhibits free radical-induced peroxidation of brain homogenate, microsomes, mitochondria, amino acids, deoxyribose and DNA. The in-vivo study with immobilization-induced emotional stress in rats, showed that YZYS effectively inhibits stress-induced stomach ulcers and oxidative damage in plasma and the brain. In addition, YZYS is shown to be non-toxic in both acute and chronic toxicity tests. These studies demonstrate that YZYS is a potent natural antioxidant and offer theoretical evidence for the beneficial effect of YZYS on health and brain functions, and that TCM prescriptions can be studied scientifically as modern medical drugs.

scholarly journals In vitro Metabolism of Steroid Hormones by Chicken Kidney

1979 ◽  
Vol 16 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Takao NAKAMURA ◽  
Yuichi TANABE ◽  
Osamu KATO
Keyword(s):  
Steroid Hormones ◽  
In Vitro Metabolism ◽  
Chicken Kidney

scholarly journals In vitro Metabolism of Steroid Hormones by Chicken Oviduct

1978 ◽  
Vol 15 (3) ◽  
pp. 108-113 ◽  
Author(s):  
Takao NAKAMURA ◽  
Yuichi TANABE
Keyword(s):  
Steroid Hormones ◽  
In Vitro Metabolism ◽  
Chicken Oviduct

scholarly journals In vivo activity of glutaminase in the brain of hyperammonaemic rats measured by 15N nuclear magnetic resonance

1995 ◽  
Vol 305 (1) ◽  
pp. 329-336 ◽  
Author(s):  
K Kanamori ◽  
B D Ross
Keyword(s):  
Brain Homogenate ◽  
Inhibitory Effect ◽  
Intact Brain ◽  
Strong Inhibitory Effect ◽  
Glutamine Synthesis ◽  
Gaba Synthesis ◽  
The Brain

The in vivo activity of phosphate-activated glutaminase (PAG) was measured in the brain of hyperammonaemic rat by 15N n.m.r. Brain glutamine was 15N-enriched by intravenous infusion of 15NH4+ until the concentration of [5-15N]glutamine reached 6.1 mumol/g. Further glutamine synthesis was inhibited by intraperitoneal injection of methionine-DL-sulphoximine, an inhibitor of glutamine synthetase, and the infusate was changed to 14NH4+ during observation of decrease in brain [5-15N]glutamine due to PAG and other glutamine utilization pathways. Progressive decrease in brain [5-15N]glutamine, PAG-catalysed production of 15NH4+ and its subsequent assimilation into glutamate by glutamate dehydrogenase were monitored in vivo by 15N n.m.r. Brain [5-15N]glutamine (15N enrichment of 0.35-0.50) decreased at a rate of 1.2 mumol/h per g of brain. The in vivo PAG activity, determined from the observed rate and the quantity of 15NH4+ produced and subsequently assimilated into glutamate and aspartate, was 0.9-1.3 mumol/h per g. This activity is less than 1.1% of the reported activity in vitro measured in rat brain homogenate at a 10 mM concentration of the activator Pi. Inhibition by ammonia (brain level 1.4 mumol/g) alone does not account for the observed low activity in vivo. The result strongly suggests that, in intact brain, PAG activity is maintained at a low level by a suboptimal in situ concentration of Pi and the strong inhibitory effect of glutamate. The observed PAG activity in vivo is lower than the reported in vivo activity of glutamate decarboxylase which converts glutamate into gamma-aminobutyrate (GABA). The result suggests that PAG-catalysed hydrolysis of glutamine is not the sole provider of glutamate used for GABA synthesis.

scholarly journals In vitro Metabolism of Steroid Hormones by Rodent Submaxillary Gland

1980 ◽  
Vol 51 (3) ◽  
pp. 159-164
Author(s):  
Hideo KATSUKAWA ◽  
Takao NAKAMURA ◽  
Yuichi TANABE
Keyword(s):  
Steroid Hormones ◽  
Submaxillary Gland ◽  
In Vitro Metabolism

First in vitro isolation of Neospora caninum from a naturally infected adult dairy cow in Slovakia

2011 ◽  
Vol 56 (2) ◽  
Author(s):  
Katarína Reiterová ◽  
Silvia Špilovská ◽  
Andrea Čobádiová ◽  
Rastislav Mucha
Keyword(s):  
Dairy Cow ◽  
Neospora Caninum ◽  
Brain Homogenate ◽  
Vero Cells ◽  
Meriones Unguiculatus ◽  
Post Inoculation ◽  
Mongolian Gerbils ◽  
The Impact ◽  
The Brain

AbstractThe impact of in vitro isolation and molecular characterisation of Neospora caninum as well as sequence analyses was studied. The brain homogenate of a naturally Neospora-infected dairy cow (positive in ELISA and Western blot) was intraperitoneally inoculated into Mongolian gerbils (Meriones unguiculatus). The brain of gerbils on day 60 post-inoculation was homogenized, and, after trypsin-digestion, cultured on Vero cells. Neospora-like tachyzoites were first observed after 77 days of cultivation. The parasite was confirmed by polymerase chain reaction (PCR) using Neospora-specific primers Np21 and Np6. The PCR product of the first Slovak isolate (NC-SKB1) was subsequently sequenced and published in GenBank under accession number GU300774. Sequencing and BLAST search identified the isolate as N. caninum.

scholarly journals Direct observation of microtubule treadmilling by electron microscopy.

1985 ◽  
Vol 101 (5) ◽  
pp. 1637-1642 ◽  
Author(s):  
S W Rothwell ◽  
W A Grasser ◽  
D B Murphy
Keyword(s):  
Electron Microscopy ◽  
Exchange Rate ◽  
Direct Observation ◽  
Flux Rate ◽  
Chicken Brain ◽  
Critical Concentrations ◽  
Tubulin Subunit ◽  
The Brain ◽  
Brain Tubulin

Using an immunoelectron microscopic procedure, we directly observed the concurrent addition and loss of chicken brain tubulin subunits from the opposite ends of microtubules containing erythrocyte tubulin domains. The polarity of growth of the brain tubulin on the ends of erythrocyte microtubules was determined to be similar to growth off the ends of Chlamydomonas axonemes. The flux rate for brain tubulin subunits in vitro was low, approximately 0.9 micron/h. Tubulin subunit flux did not continue through the entire microtubule as expected, but ceased when erythrocyte tubulin domains became exposed, resulting in a metastable configuration that persisted for at least several hours. We attribute this to differences in the critical concentrations of erythrocyte and brain tubulin. The exchange of tubulin subunits into the walls of preformed microtubules other than at their ends was also determined to be insignificant, the exchange rate being less than the sensitivity of the assay, or less than 0.2%/h.

scholarly journals In vitro Metabolism of Steroid Hormones by Rodent Submaxillary Gland

1980 ◽  
Vol 51 (3) ◽  
pp. 165-170
Author(s):  
Hideo KATSUKAWA ◽  
Takao NAKAMURA ◽  
Yuichi TANABE
Keyword(s):  
Steroid Hormones ◽  
Submaxillary Gland ◽  
In Vitro Metabolism

scholarly journals New In Vitro Methodology for Kinetics Distribution Prediction in the Brain. An Additional Step towards an Animal-Free Approach

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3521
Author(s):  
Bárbara Sánchez-Dengra ◽  
Isabel González-Álvarez ◽  
Marta González-Álvarez ◽  
Marival Bermejo
Keyword(s):  
Brain Homogenate ◽  
Apparent Volume ◽  
Volume Of Distribution ◽  
New Drugs ◽  
In Vitro Tests ◽  
Unbound Fraction ◽  
Standard Tool ◽  
New Formulation ◽  
The Brain

The development of new drugs or formulations for central nervous system (CNS) diseases is a complex pharmacologic and pharmacokinetic process; it is important to evaluate their access to the CNS through the blood−brain barrier (BBB) and their distribution once they have acceded to the brain. The gold standard tool for obtaining this information is the animal microdialysis technique; however, according to 3Rs principles, it would be better to have an “animal-free” alternative technique. Because of that, the purpose of this work was to develop a new formulation to substitute the brain homogenate in the in vitro tests used for the prediction of a drug’s distribution in the brain. Fresh eggs have been used to prepare an emulsion with the same proportion in proteins and lipids as a human brain; this emulsion has proved to be able to predict both the unbound fraction of drug in the brain (fu,brain) and the apparent volume of distribution in the brain (Vu,brain) when tested in in vitro permeability tests. The new formulation could be used as a screening tool; only the drugs with a proper in vitro distribution would pass to microdialysis studies, contributing to the refinement, reduction and replacement of animals in research.

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