Effect of stress and the antioxidant ionol on catecholamine synthesis and the dopamine concentration in the heart and adrenals

1987 ◽  
Vol 104 (6) ◽  
pp. 1661-1664
Author(s):  
F. Z. Meerson ◽  
V. V. Malyshev ◽  
E. B. Manukhina ◽  
V. A. Petrova
Keyword(s):  
Dopamine Concentration ◽  
Catecholamine Synthesis ◽  
Antioxidant Ionol

Decreased Platelet-Free Dopamine and Unchanged Noradrenaline and Adrenaline in Essential Hypertension

1988 ◽  
Vol 60 (02) ◽  
pp. 251-254 ◽  
Author(s):  
S E Kjeldsen ◽  
K Gjesdal ◽  
P Leren ◽  
I K Eide
Keyword(s):  
Body Weight ◽  
Essential Hypertension ◽  
Blood Platelets ◽  
Plasma Catecholamine ◽  
Catecholamine Synthesis ◽  
Hypertensive Group ◽  
Plasma Catecholamine Concentrations ◽  
Noradrenaline And Adrenaline ◽  
Over Time ◽  
Normotensive Control

SummaryThe content of free-catecholamines in blood platelets is much higher than in plasma and platelet catecholamines must be taken up from plasma, since platelets lack the enzymes for catecholamine synthesis. There is some evidence that platelet catecholamine content under certain circumstances may be an integrated measure of plasma catecholamine concentrations over time. Platelet-free catecholamines were therefore assayed in 18 untreated patients with essential hypertension and in 16 normotensive control subjects. Mean platelet-free dopamine in the hypertensive group was 3.7 ± 0.4 pg/mg platelet weight, i.e. significantly less than the 6.5 ± 0.9 pg/mg found in the normotensive (p <0.005). Platelet contents of noradrenaline and adrenaline did not differ. Decreased platelet-free dopamine and unchanged platelet noradrenaline and adrenaline persisted after adjustment for increased body weight in the hypertensive group. Although the reasons for decreased platelet-free dopamine in the hypertensive group remain unknown, this finding may add to previous result showing facilitated release of granular contents from blood platelets in patients with essential hypertension. Our data do not support platelet levels of free-catecholamines to be a marker of increased sympathetic tone in essential hypertension.

Non-Cottrell Behavior of the Dopamine Redox Reaction Observed on the Carbon Fibre Microelectrode by the Double-Step Voltcoulometry

2004 ◽  
Vol 69 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Katarína Gmucová ◽  
Jozef Orlický ◽  
Juraj Pavlásek
Keyword(s):  
Carbon Fibre ◽  
Redox Reaction ◽  
Measured Data ◽  
The Other ◽  
Diffusion Current ◽  
Double Step ◽  
Dopamine Concentration ◽  
Living Body ◽  
Carbon Fibre Microelectrode ◽  
Experimental Errors

The redox reaction of the neurotransmitter dopamine at the carbon fibre microelectrode was studied by several electrochemical methods. It was found that under conditions usual in a living body, the diffusion current fullfils, within experimental errors, the behavior theoretically predicted by the Cottrell equation. Nevertheless, attention should be paid to the fact that unsupported or weakly supported conditions give rise to a non-Cottrell response of diffusion current. Moreover, similar changes were observed if the dopamine concentration was either lower such as several units of μmol l-1, or about 100 μmol l-1 or higher. The non-Cottrell behavior of diffusion current involves the nonlinearity of the dopamine calibration curve obtained by pulse techniques. The present work is aimed at pointing out that such behavior of the measured data could lead to misinterpretation of the obtained dopamine concentration. Similar features could be also achieved for the other catecholamines.

scholarly journals Evaluation of Enzyme Inhibitory Activity of Flavonoids by Polydopamine-Modified Hollow Fiber-Immobilized Xanthine Oxidase

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3931
Author(s):  
Cong-Peng Zhao ◽  
Guo-Ying Chen ◽  
Yuan Wang ◽  
Hua Chen ◽  
Jia-Wen Yu ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Hollow Fiber ◽  
Inhibitory Activity ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Amino Acid Residues ◽  
Reaction Conditions ◽  
Docking Analysis ◽  
Dopamine Concentration ◽  
Immobilization Time

In this study, a polydopamine (PDA)-modified hollow fiber-immobilized xanthine oxidase (XOD) was prepared for screening potential XOD inhibitors from flavonoids. Several parameters for the preparation of PDA-modified hollow fiber-immobilized XOD, including the dopamine concentration, modification time, XOD concentration and immobilization time, were optimized. The results show that the optimal conditions for immobilized XOD activity were a dopamine concentration of 2.0 mg/mL in 10.0 mM Tris-HCl buffer (pH 8.5), a modification time of 3.0 h, an XOD concentration of 1000 μg/mL in 10.0 mM phosphate buffer (pH 7.5) and an immobilization time of 3.0 h. Subsequently, the enzymatic reaction conditions such as the pH value and temperature were investigated, and the enzyme kinetics and inhibition parameters were determined. The results indicate that the optimal pH value (7.5) and temperature (37 °C) of the PDA-modified hollow fiber-immobilized XOD were consistent with the free enzyme. Moreover, the PDA-modified hollow fiber-immobilized XOD could still maintain above 50% of its initial immobilized enzyme activity after seven consecutive cycles. The Michaelis–Menten constant (Km) and the half-maximal inhibitory concentration (IC50) of allopurinol on the immobilized XOD were determined as 0.25 mM and 23.2 μM, respectively. Furthermore, the PDA-modified hollow fiber-immobilized XOD was successfully applied to evaluate the inhibitory activity of eight flavonoids. Quercetin, apigenin, puerarin and epigallocatechin showed a good inhibition effect, and their percentages of inhibition were (79.86 ± 3.50)%, (80.98 ± 0.64)%, (61.15 ± 6.26)% and (54.92 ± 0.41)%, respectively. Finally, molecular docking analysis further verified that these four active compounds could bind to the amino acid residues in the XOD active site. In summary, the PDA-modified hollow fiber-immobilized XOD is an efficient method for the primary screening of XOD inhibitors from natural products.

scholarly journals Smoking-induced change in intrasynaptic dopamine concentration: Effect of treatment for Tobacco Dependence

2010 ◽  
Vol 183 (3) ◽  
pp. 218-224 ◽  
Author(s):  
Arthur L. Brody ◽  
Edythe D. London ◽  
Richard E. Olmstead ◽  
Zoe Allen-Martinez ◽  
Stephanie Shulenberger ◽  
...  
Keyword(s):  
Tobacco Dependence ◽  
Concentration Effect ◽  
Dopamine Concentration ◽  
Effect Of Treatment

Estimation from PET data of transient changes in dopamine concentration induced by alcohol: support for a non-parametric signal estimation method

2008 ◽  
Vol 53 (5) ◽  
pp. 1353-1367 ◽  
Author(s):  
C C Constantinescu ◽  
K K Yoder ◽  
D A Kareken ◽  
C A Bouman ◽  
S J O'Connor ◽  
...  
Keyword(s):  
Estimation Method ◽  
Signal Estimation ◽  
Dopamine Concentration ◽  
Non Parametric

Tyrosine hydroxylase-containing neurons in the spinal cord of the chicken. I. Development and analysis of catecholamine synthesis capabilities

1996 ◽  
Vol 16 (6) ◽  
pp. 625-648 ◽  
Author(s):  
James A. Wallace ◽  
Audrey A. Romero ◽  
Anna M. Gabaldon ◽  
Victoria A. Roe ◽  
Sandra L. Saavedra ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Tyrosine Hydroxylase ◽  
Catecholamine Synthesis

Deep brain stimulation of the subthalamic nucleus does not increase the striatal dopamine concentration in parkinsonian humans

2003 ◽  
Vol 18 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Ruediger Hilker ◽  
Juergen Voges ◽  
Mehran Ghaemi ◽  
Ralf Lehrke ◽  
Jobst Rudolf ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Striatal Dopamine ◽  
Dopamine Concentration ◽  
Deep Brain ◽  
Stimulation Of
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