Effect of Unconjugated and Conjugated Phenol and Uraemia on the Synthesis of Adenosine 3′:5′-Cyclic Monophosphate in Rat Brain Homogenates

1978 ◽  
Vol 55 (3) ◽  
pp. 271-275
Author(s):  
G. A. Turner ◽  
E. N. Wardle
Keyword(s):  
Rat Brain ◽  
Adenyl Cyclase ◽  
Cortical Response ◽  
Depressive Effect ◽  
Cyclic Monophosphate ◽  
Normal Rat ◽  
The Brain

1. The effects of phenol and phenyl glucuronide on the responses of normal rat brain adenyl cyclase to noradrenaline and dopamine have been investigated. Neurotransmitter responses have also been examined in brains from uraemic and normal rats. 2. A depressive effect of phenol on the adenosine 3′: 5′-cyclic monophosphate response of the neostriatum to dopamine was shown to be completely abolished if the toxin was present in the conjugated form; the response of the cortex to noradrenaline was stimulated by the presence of phenyl glucuronide, even though the unconjugated form had no effect. 3. The uraemic state in the rat also resulted in a depression of the neostriatum response to dopamine, yet an enhancement of the cortical response to noradrenaline. 4. The action of phenols on the brain is relevant to hepatic and uraemic coma.

Urinary Cyclic AMP in ‘Endogenous' and ‘Neurotic’ Depression

1975 ◽  
Vol 126 (1) ◽  
pp. 49-55 ◽  
Author(s):  
K. Sinanan ◽  
A. M. B. Keatinge ◽  
P. G. S. Beckett ◽  
W. Clayton Love
Keyword(s):  
Cyclic Amp ◽  
Second Messenger ◽  
Adenyl Cyclase ◽  
Induced Responses ◽  
High Concentration ◽  
Cyclic Monophosphate ◽  
Cyclic Amp Phosphodiesterase ◽  
Urinary Cyclic Amp ◽  
The Brain

Since the discovery of adenosine 3'5'-cyclic monophosphate (cyclic AMP) by Sutherland and Rall (1958), the concept has evolved that this nucleotide acts as the second messenger substance for many neurotransmitter and hormone-induced responses (Sutherland, Robison and Butcher, 1968). Cyclic AMP occurs in high concentration in the brain. Cyclic AMP is functionally closely related, and possibly fundamental, to the action of catecholamines and serotonin, both of which have been implicated in the amine hypothesis of depression (Granville-Grossman, 1971). Cyclic AMP is formed from ATP by the action of an enzyme adenyl cyclase, and it is degraded by the enzyme cyclic-AMP-phosphodiesterase (Lancet, Editorial, 1970) both of which occur in brain.

scholarly journals The Transfer Coefficients for L-Valine and the Rate of Incorporation of L-[1-14C] Valine into Proteins in Normal Adult Rat Brain

1988 ◽  
Vol 8 (4) ◽  
pp. 598-605 ◽  
Author(s):  
M. Kirikae ◽  
M. Diksic ◽  
Y. L. Yamamoto
Keyword(s):  
White Matter ◽  
Rat Brain ◽  
Inferior Colliculus ◽  
Gray Matter ◽  
Transfer Coefficients ◽  
Brain Proteins ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Normal Rat ◽  
The Brain

An autoradiographic method for the measurement of the rate of valine incorporation into brain proteins is described. The transfer coefficients for valine into and out of the brain and the rate of valine incorporation into normal rat brain proteins are given. The valine incorporation and the transfer constants of valine between different biological compartments are provided for 14 gray matter and 2 white matter structures of an adult rat brain. The rate of valine incorporation varies between 0.52 ± 0.19 nmol/g/min in white matter and 1.94 ± 0.47 in inferior colliculus (gray matter). Generally, the rate of valine incorporation is about three to four times higher in the gray matter than in the white matter structures.

Angiogenesis Induced by Photodynamic Therapy in Normal Rat Brain¶

2004 ◽  
Vol 79 (6) ◽  
pp. 494 ◽  
Author(s):  
Feng Jiang ◽  
Zheng Gang Zhang ◽  
Mark Katakowski ◽  
Adam M Robin ◽  
Michelle Faber ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Rat Brain ◽  
Normal Rat

Liquid Chromatography Analysis of Clozapine in Rat Brain Tissue, Using its Molecularly Imprinted Polymer after Administration of Toxic Dose of Drug and Lipid Emulsion Therapy

2019 ◽  
Vol 15 (3) ◽  
pp. 251-257
Author(s):  
Bahareh Sadat Yousefsani ◽  
Seyed Ahmad Mohajeri ◽  
Mohammad Moshiri ◽  
Hossein Hosseinzadeh
Keyword(s):  
Rat Brain ◽  
Brain Tissue ◽  
Molecularly Imprinted Polymer ◽  
Lipid Emulsion ◽  
Limit Of Detection ◽  
Imprinted Polymer ◽  
Toxic Dose ◽  
Molecularly Imprinted ◽  
The Brain ◽  
Rat Brain Tissue

Background:Molecularly imprinted polymers (MIPs) are synthetic polymers that have a selective site for a given analyte, or a group of structurally related compounds, that make them ideal polymers to be used in separation processes.Objective:An optimized molecularly imprinted polymer was selected and applied for selective extraction and analysis of clozapine in rat brain tissue.Methods:A molecularly imprinted solid-phase extraction (MISPE) method was developed for preconcentration and cleanup of clozapine in rat brain samples before HPLC-UV analysis. The extraction and analytical process was calibrated in the range of 0.025-100 ppm. Clozapine recovery in this MISPE process was calculated between 99.40 and 102.96%. The limit of detection (LOD) and the limit of quantification (LOQ) of the assay were 0.003 and 0.025 ppm, respectively. Intra-day precision values for clozapine concentrations of 0.125 and 0.025 ppm were 5.30 and 3.55%, whereas inter-day precision values of these concentrations were 9.23 and 6.15%, respectively. In this study, the effect of lipid emulsion infusion in reducing the brain concentration of drug was also evaluated.Results:The data indicated that calibrated method was successfully applied for the analysis of clozapine in the real rat brain samples after administration of a toxic dose to animal. Finally, the efficacy of lipid emulsion therapy in reducing the brain tissue concentration of clozapine after toxic administration of drug was determined.Conclusion:The proposed MISPE method could be applied in the extraction and preconcentration before HPLC-UV analysis of clozapine in rat brain tissue.

scholarly journals High Glycogen Levels in Brains of Rats with Minimal Environmental Stimuli: Implications for Metabolic Contributions of Working Astrocytes

2002 ◽  
Vol 22 (12) ◽  
pp. 1476-1489 ◽  
Author(s):  
Nancy F. Cruz ◽  
Gerald A. Dienel
Keyword(s):  
Rat Brain ◽  
Sensory Stimulation ◽  
Enzyme Inactivation ◽  
Biologically Active ◽  
Metabolic Labeling ◽  
Tissue Sampling ◽  
Normal Rat ◽  
Sampling Procedures ◽  
Very High

The concentration of glycogen, the major brain energy reserve localized mainly in astrocytes, is generally reported as about 2 or 3 μmol/g, but sometimes as high as 3.9 to 8 μmol/g, in normal rat brain. The authors found high but very different glycogen levels in two recent studies in which glycogen was determined by the routine amyloglucosidase procedure in 0.03N HCl digests either of frozen powders (4.8 to 6 μmol/g) or of ethanol-insoluble fractions (8 to 12 μmol/g). To evaluate the basis for these discrepant results, glycogen was assayed in parallel extracts of the same samples. Glycogen levels in ethanol extracts were twice those in 0.03N HCl digests, suggesting incomplete enzyme inactivation even with very careful thawing. The very high glycogen levels were biologically active and responsive to physiologic and pharmacological challenge. Glycogen levels fell after brief sensory stimulation, and metabolic labeling indicated its turnover under resting conditions. About 95% of the glycogen was degraded under in vitro ischemic conditions, and its “carbon equivalents” recovered mainly as glc, glc-P, and lactate. Resting glycogen stores were reduced by about 50% by chronic inhibition of nitric oxide synthase. Because neurotransmitters are known to stimulate glycogenolysis, stress or sensory activation due to animal handling and tissue-sampling procedures may stimulate glycogenolysis during an experiment, and glycogen lability during tissue sampling and extraction can further reduce glycogen levels. The very high glycogen levels in normal rat brain suggest an unrecognized role for astrocytic energy metabolism during brain activation.

scholarly journals High-Cholesterol Diet Decreases the Level of Phosphatidylinositol 4,5-Bisphosphate by Enhancing the Expression of Phospholipase C (PLCβ1) in Rat Brain

2020 ◽  
Vol 21 (3) ◽  
pp. 1161 ◽  
Author(s):  
Yoon Sun Chun ◽  
Sungkwon Chung
Keyword(s):  
Neurodegenerative Diseases ◽  
Rat Brain ◽  
Phospholipase C ◽  
Cultured Cells ◽  
Cell Interaction ◽  
High Cholesterol Diet ◽  
Cholesterol Diet ◽  
High Cholesterol ◽  
Amyloid Aβ ◽  
The Brain

Cholesterol is a critical component of eukaryotic membranes, where it contributes to regulating transmembrane signaling, cell–cell interaction, and ion transport. Dysregulation of cholesterol levels in the brain may induce neurodegenerative diseases, such as Alzheimer’s disease, Parkinson disease, and Huntington disease. We previously reported that augmenting membrane cholesterol level regulates ion channels by decreasing the level of phosphatidylinositol 4,5-bisphosphate (PIP2), which is closely related to β-amyloid (Aβ) production. In addition, cholesterol enrichment decreased PIP2 levels by increasing the expression of the β1 isoform of phospholipase C (PLC) in cultured cells. In this study, we examined the effect of a high-cholesterol diet on phospholipase C (PLCβ1) expression and PIP2 levels in rat brain. PIP2 levels were decreased in the cerebral cortex in rats on a high-cholesterol diet. Levels of PLCβ1 expression correlated with PIP2 levels. However, cholesterol and PIP2 levels were not correlated, suggesting that PIP2 level is regulated by cholesterol via PLCβ1 expression in the brain. Thus, there exists cross talk between cholesterol and PIP2 that could contribute to the pathogenesis of neurodegenerative diseases.

scholarly journals THE LOCALIZATION OF ENZYME ACTIVITIES IN THE RAT BRAIN

1960 ◽  
Vol 8 (3) ◽  
pp. 649-663 ◽  
Author(s):  
Norwin H. Becker ◽  
Sidney Goldfischer ◽  
Woo-Yung Shin ◽  
Alex B. Novikoff
Keyword(s):  
Rat Brain ◽  
Cell Membranes ◽  
Reductase Activity ◽  
Frozen Sections ◽  
Fixed Tissue ◽  
Quantitative Histochemistry ◽  
Capillary Endothelial Cells ◽  
Intracellular Organelles ◽  
The Brain ◽  
Nissl Substance

Studies with rat brain illustrate the usefulness of formol-calcium-fixed tissue for studying both enzymatic "chemoarchitectonics" and intracellular organelles. Unembedded frozen sections and polyvinyl alcohol-embedded sections may be used to demonstrate the activities of DPNH-tetrazolium reductase localized in mitochondria and ergastoplasm, TPNH-tetrazolium reductase localized in mitochondria, ATPase (and/or apyrase or ADPase) in cell membranes, and acid phosphatase in lysosomes.1 Among the observations recorded are: (1) the presence of lysosomes in all cells of the brain; (2) the presence of numerous large lysosomes near the nuclei of capillary endothelial cells; (3) a polarized arrangement of large lysosomes in epithelial cells of the ependyma and choroid plexus; (4) the presence of ATPase activity in the cell membranes of some neurons; (5) the presence of either an apyrase or combination of ATPase and ADPase in the cell membranes of neuroglia and capillaries; (6) the presence of both DPNH- and TPNH-tetrazolium reductase activities in neuroglia; (7) the presence of DPNH- and TPNH-tetrazolium reductase activities in mitochondria and of DPNH-tetrazolium reductase activity in Nissl substance. The possible functional significance of these localizations is briefly discussed, as is their relation to "quantitative histochemistry" data available in the literature.

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