THE BICARBONATE/CARBONIC ACID BUFFER SYSTEM OF THE CEREBRAL CORTEX OF CATS, AS STUDIED IN TISSUE HOMOGENATES

2009 ◽  
Vol 38 (2) ◽  
pp. 121-141 ◽  
Author(s):  
Bo K. Siesjö
Keyword(s):  
Cerebral Cortex ◽  
Carbonic Acid ◽  
Buffer System ◽  
Acid Buffer ◽  
Acid Buffer System ◽  
Tissue Homogenates

scholarly journals Oligosaccharide-based Surfactant/Citric Acid Buffer System Stabilizes Lactate Dehydrogenase during Freeze-drying and Storage without the Addition of Natural Sugar

2016 ◽  
Vol 65 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Shigesaburo Ogawa ◽  
Ryuichiro Kawai ◽  
Maito Koga ◽  
Kouichi Asakura ◽  
Isao Takahashi ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Citric Acid ◽  
Freeze Drying ◽  
Buffer System ◽  
Acid Buffer ◽  
Citric Acid Buffer ◽  
Acid Buffer System ◽  
And Storage

Contribution from local conversion of thyroxine to 3,5,3'-triiodothyronine to intracellular 3,5,3'-triiodothyronine in several organs in hypothyroid rats at isotope equilibrium

1982 ◽  
Vol 101 (3) ◽  
pp. 386-396 ◽  
Author(s):  
J. van Doom ◽  
F. Roelfsema ◽  
D. van der Heide
Keyword(s):  
Cerebral Cortex ◽  
Pituitary Gland ◽  
Subcellular Fractions ◽  
Thigh Muscle ◽  
Intracellular Level ◽  
Carrier Free ◽  
Tissue Homogenates ◽  
Isotope Equilibrium ◽  
Layer Chromatography ◽  
The Brain

Abstract. The intracellular conversion of T4 to T3 was investigated in various tissues of hypothyroid rats after continuous iv infusion of radiolabelled T3 and T4. Two groups of 4 thyroidectomized rats were infused with carrier-free 125I-labelled T4 as well as 131I-labelled T3 until isotope equilibrium was achieved. Plasma, various tissue homogenates (liver, kidney, pituitary, thigh muscle, cerebral cortex and cerebellum) and subcellular fractions (nuclei, mitochondria, microsomes, cytoplasm) from liver, kidney and the pituitary gland were extracted for thin layer chromatography. The [125I]T3/[131I]T3 ratios were determined and the extra contribution of [125I]T3 derived from local conversion of [125I]T4 to the total [125I]T3 was calculated in percent. In addition to the [125I]T3 derived from plasma, [125I]T3 derived from locally converted [125I]T4 was present in all tissues investigated. There was substantially more, although in varying quantities, in the cerebral cortex (79 ± 2%), the cerebellum (68 ± 4%) and the pituitary gland (53 ± 1%) than in the liver (10 ± 6%), the kidney (11 ± 5%) and thigh muscle (17 ± 6%); in the latter tissues most of the 125I-labelled T3 is derived directly from plasma. These results indicate that in the brain of severe hypothyroid rats there is pronounced conversion of T4 to T3 and effective binding of the T3 produced whereas the T3 in the liver, kidney, and muscle is predominantly derived from plasma. At the intracellular level, within the investigated tissues, the locally formed T3 was distributed equally over the subcellular fractions.

scholarly journals Monoaminergic Involvement in Decreased Locomotor Activity of Mice Treated with α and β-amyrin from Protium heptaphyllum

2018 ◽  
Vol 13 (8) ◽  
pp. 1934578X1801300
Author(s):  
Gislei F. Aragão ◽  
Manoel O. de Moraes Filho ◽  
Paulo N. Bandeira ◽  
Antônio P. Frota Junior ◽  
Yasmin Ingrid S. Oliveira de ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity ◽  
Open Field ◽  
Field Test ◽  
High Performance ◽  
Open Field Test ◽  
Inhibitory Effect ◽  
Pharmacological Agents ◽  
Tissue Homogenates ◽  
The Central Nervous System

A triterpenic mixture of α and β-amyrin (AMY) extracted from Protium heptaphyllum has demonstrated several pharmacological effects, including activity in the central nervous system. The aim of this study was to evaluate the effect of AMY administration on locomotor activity of mice by the open field test using some monoaminergic agonists and antagonists and the cerebral cortex levels of monoamines and their major metabolites by high-performance liquid chromatography. Mice were treated acutely with AMY at doses of 1, 2.5 and 5 mg/kg given intraperitoneally and with the pharmacological agents and placed in open field test, then the animals were sacrificed and the cerebral cortex extracted, and monoamines were assayed in tissue homogenates. AMY at 1, 2.5 and 5 mg/kg decreased locomotor activity of animals by 25, 31 and 39%, respectively in the open field test. Ondasentron, doxazosin, oxymetazoline and clonidine did not reverse the inhibitory effect of 5 mg/kg AMY. Venlafaxine and yohimbine reversed the inhibitory effect of 5 mg AMY. In the cortex, the 5-HT and 5-HIAA were significantly reduced by the administration of AMY. NE and HVA were also reduced with 2.5 and 5 mg/kg AMY, while Dopamine and DOPAC were not increased with AMY. In conclusion, AMY decreased locomotor activity of animals accompanied by a decrease in 5-HT and NE levels in the cerebral cortex, this locomotor effect is reversed by drug that blocker the α-2-adrenoreceptor.

Analytical Methods for Diethylstilbestrol in Feeds and Premixes

1966 ◽  
Vol 49 (5) ◽  
pp. 895-898
Author(s):  
Loyal R Stone
Keyword(s):  
Acetic Acid ◽  
Analytical Methods ◽  
Sodium Acetate ◽  
Buffer System ◽  
Official Method ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Acid Buffer System ◽  
Acetic Acid Buffer

Abstract Methods are presented in which diethylstilbestrol is extracted from feeds in the Goldfisch apparatus, transferred into alkaline sodium acetate solution to avoid emulsions, and measured colorimetrically in a sodium acetate-acetic acid buffer system. The procedure is rapid, and results agree closely with those obtained by the official method. Procedures are also presented for determination of diethylstilbestrol in molasses and fat mixtures.

Some Characteristics of the Clottable Protein of Limulus Polyphemus Blood Cells

1970 ◽  
Vol 23 (01) ◽  
pp. 170-181 ◽  
Author(s):  
N. O Solum
Keyword(s):  
Disc Electrophoresis ◽  
Cell Protein ◽  
Total Amino Acid ◽  
Molecular Characteristics ◽  
Buffer System ◽  
Starch Gel Electrophoresis ◽  
Cell Extracts ◽  
Minimal Molecular Weight ◽  
Acid Buffer System ◽  
Starch Gel

Summary1. The endotoxin-clottable protein of Limulus blood cell extracts has been studied. The concept of the clottable protein as a true cell protein was confirmed.2. 35–55% of total extractable protein was removed from the extracts by clotting. Polyacrylamide disc electrophoresis of the extracts showed 6 to 9 protein bands one of which was reduced in intensity by the clotting. Dimethylf ormamide could be used for fractionated precipitation of the proteins.3. The gel protein was easily soluble in HCl or NaOH and reprecipitated by neutralization. It was also soluble in 0.05 M formate/6.7 M urea pH 4.3 but not in neutral solutions of urea.4. Light absorption spectra of the gel protein in 0.188 N NaOH showed maxima at 283 mμ and 290 mμ, whereas one maximum, at 276 mμ, was observed in 0.189 N HCl. E1 % 1 cm in 0.188 N NaOH was 10.4 and 11.1 at 283 mμ and 290 mμ, respectively, and 9.0 at 276 mμ in 0.189 N HCl.5. Data on the total amino acid composition of the gel protein are given. A mean minimal molecular weight of about 20,000 is calculated from these.6. In starch gel electrophoresis with a discontinuous acid buffer system the gel protein separated into two main zones. Possible relationships between these are discussed in terms of clotting mechanism.7. The data show that Limulus clottable protein differs markedly in its molecular characteristics from those of mammalian fibrinogens.

scholarly journals Expression of 5α-Reductase in the Human Temporal Lobe of Children and Adults1

1998 ◽  
Vol 83 (10) ◽  
pp. 3636-3642
Author(s):  
Birgit Stoffel-Wagner ◽  
Matthias Watzka ◽  
Stephan Steckelbroeck ◽  
Lucia Wickert ◽  
Johannes Schramm ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Temporal Lobe ◽  
Reductase Activity ◽  
Biological Effects ◽  
Subcortical White Matter ◽  
Rt Pcr ◽  
Messenger Ribonucleic Acid ◽  
Tissue Homogenates ◽  
The Brain ◽  
Human Temporal Lobe

Androgens exert important biological effects on the brain, and 5α-reductase plays a crucial role in androgen metabolism. Therefore, we investigated the expression of the two isozymes of 5α-reductase in the human temporal lobe to determine the predominant isoform and to elucidate the existence of possible sex differences and differences between children and adults. We studied biopsy materials from the temporal lobe of 34 women, 32 men, and 12 children. Quantification of 5α-reductase 1 and 2 messenger ribonucleic acid (mRNA) was achieved by competitive RT-PCR. 5α-Reductase activity was determined in tissue homogenates using [1,2-3H]androstenedione as the substrate. Only 5α-reductase 1 mRNA was expressed in human temporal lobe tissue; 5α-reductase 2 mRNA was not expressed. 5α-Reductase 1 mRNA concentrations did not differ significantly in the cerebral cortex of women [25.9 ± 7.9 arbitrary units (aU); mean ± sem] and men (20.4 ± 2.8 aU) or in the cerebral cortex (23.3 ± 4.4 aU) and the subcortical white matter of adults (32.6 ± 5.6 aU), but they were significantly higher in the cerebral cortex of adults than in that of children (6.4 ± 2.3 aU; P < 0.005). The apparent Km of 5α-reduction did not show significant differences between the two sexes. In conclusion, 5α-reductase 1 mRNA is expressed in the temporal lobe of children and adults, but 5α-reductase 2 mRNA is not. 5α-Reductase 1 mRNA concentrations did not differ significantly in the sexes, but they were significantly higher in specimens of adults than in those of children.

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