In vivo studies on the conversion of m-tyrosine to 3,4-dihydroxyphenylalanine in the rat

1977 ◽  
Vol 55 (10) ◽  
pp. 1103-1107 ◽  
Author(s):  
J. H. Tong ◽  
R. G. Smyth ◽  
N. L. Benoiton ◽  
A. D'Iorio
Keyword(s):  
Rat Brain ◽  
Enzyme Inhibitors ◽  
Phenylalanine Hydroxylase ◽  
Intraperitoneal Administration ◽  
In Vivo Studies ◽  
Dopa Decarboxylase ◽  
Decarboxylase Inhibitor ◽  
Specific Enzyme ◽  
Dihydroxyphenylacetic Acid

The question whether m-tyrosine can give rise to catechols in vivo has been investigated using labelled precursor. DL-[2-l4C]m-tyrosine (38 μCi/mmol (1 Ci = 37 GBq)) was synthesized from [2-14C]glycine. Radioactive catechols in rat brain, liver, and kidneys were examined 15 min after intraperitoneal administration of DL-[2-14C]m-tyrosine (100 mg/kg). The kidney was the only organ which showed demonstrable amounts of radioactive catechols, and about 14% of the catechols formed was identified as 3,4-dihydroxyphenylalanine (dopa), 22% as 3,4-dihydroxyphenylacetic acid, and 56% as dopamine. However, when the animals were pretreated with dopa decarboxylase inhibitor, labelled catechols were also observed in liver and brain, and dopa accounted for over 95% of the catechols formed in all three organs examined. Thus it is clear that m-tyrosine can be hydroxylated in vivo. Results from experiments using [2-14C]m-tyrosine enantiomers and specific enzyme inhibitors suggest that phenylalanine hydroxylase could be the enzyme catalyzing this reaction.

scholarly journals Phenethylamines in brain and liver of rats with experimentally induced phenylketonuria-like characteristics

1973 ◽  
Vol 132 (1) ◽  
pp. 95-100 ◽  
Author(s):  
David J. Edwards ◽  
Karl Blau
Keyword(s):  
Monoamine Oxidase ◽  
Rat Brain ◽  
Phenylalanine Hydroxylase ◽  
Brain Regions ◽  
Subcellular Fractions ◽  
Brain Cells ◽  
Blood Phenylalanine ◽  
Low Concentrations ◽  
Experimentally Induced

1. Phenethylamines were extracted from brain and liver of rats with phenylketonuria-like characteristics produced in vivo by inhibition of phenylalanine hydroxylase (EC 1.14.3.1) with p-chlorophenylalanine, with or without phenylalanine administration. To protect amines against oxidation by monoamine oxidase, pargyline was also administered. 2. β-Phenethylamine was the major compound found in brain and liver. β-Phenethanolamine and octopamine were also present, in lesser amounts, and the concentrations of these three amines paralleled blood phenylalanine concentrations. By comparison, tissues from control animals had only very low concentrations of these amines. 3. Small amounts of normetadrenaline, m-tyramine and 3-methoxytyramine were also found. 4. The inhibitors used, p-chlorophenylalanine and pargyline, gave rise to p-chlorophenethylamine and benzylamine respectively, the first via decarboxylation, the second probably by breakdown during extraction. 5. Distribution of phenethylamines in different brain regions and in subcellular fractions of rat brain cells was also investigated. The content of phenethylamine was highest in the striatum. 6. These findings are discussed in the light of changes occurring in human patients with uncontrolled phenylketonuria.

scholarly journals The Comparative Analysis of Antiviral Activity of Native and Modified Fucoidans from Brown Algae Fucus evanescens In Vitro and In Vivo

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 224 ◽  
Author(s):  
Natalya V. Krylova ◽  
Svetlana P. Ermakova ◽  
Vyacheslav F. Lavrov ◽  
Irina A. Leneva ◽  
Galina G. Kompanets ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Brown Algae ◽  
Biological Activities ◽  
Intraperitoneal Administration ◽  
In Vivo Studies ◽  
Mice Model ◽  
Dna And Rna ◽  
Antiviral Activities

The enzymatic depolymerization of fucoidans from brown algae allowed the production of their standardized derivatives with different biological activities. This work aimed to compare the antiviral activities of native (FeF) and modified with enzyme (FeHMP) fucoidans from F. evanescens. The cytotoxicity and antiviral activities of the FeF and FeHMP against herpes viruses (HSV-1, HSV-2), enterovirus (ECHO-1), and human immunodeficiency virus (HIV-1) in Vero and human MT-4 cell lines were examined by methylthiazolyltetrazolium bromide (MTT) and cytopathic effect (CPE) reduction assays, respectively. The efficacy of fucoidans in vivo was evaluated in the outbred mice model of vaginitis caused by HSV-2. We have shown that both FeF and FeHMP significantly inhibited virus-induced CPE in vitro and were more effective against HSV. FeF exhibited antiviral activity against HSV-2 with a selective index (SI) > 40, and FeHMP with SI ˃ 20, when they were added before virus infection or at the early stages of the HSV-2 lifecycle. Furthermore, in vivo studies showed that after intraperitoneal administration (10 mg/kg), both FeF and FeHMP protected mice from lethal intravaginal HSV-2 infection to approximately the same degree (44–56%). Thus, FeF and FeHMP have comparable potency against several DNA and RNA viruses, allowing us to consider the studied fucoidans as promising broad-spectrum antivirals.

scholarly journals Quality Assessment of Serially Ultradiluted and Agitated Drug Digitalis purpurea by Emission Spectroscopy and Clinical Analysis of Its Effect on the Heart Rate of Indian Bufo melanostictus

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Anup Sharma ◽  
Bulbul Purkait
Keyword(s):  
Heart Rate ◽  
Quality Assessment ◽  
Intraperitoneal Administration ◽  
Emission Spectra ◽  
Clinical Analysis ◽  
Point Of View ◽  
In Vivo Studies ◽  
Bufo Melanostictus ◽  
Digitalis Purpurea

The investigation of ultradiluted (homeopathic) drugs is extremely interesting and challenging, and from that point of view this study shows novelty. A study of in vivo changes in heart rate of the Indian Bufo melanostictus caused by commercially available serially ultra-diluted and agitated extract of Digitalis purpurea has been tried in order to understand their pharmacological role. RR interval (of ECG) was compared after intraperitoneal administration of serially diluted and agitated Digitalis purpurea extract, diluent rectified spirit, and Digoxin in anesthetized animals. The study revealed statistically significant changes in the heart rate after application of these drugs except in case of Digoxin and the 200th serial dilution of Digitalis purpurea. The duration of RR intervals after application of the drugs was corroborative of the effect of Digoxin and Digitalis purpurea extract up to 30th dilution. Emission spectra were obtained for the experimental ultra-diluted Digitalis purpurea extract and Digoxin to identify and characterize them. The observed RR pattern and emission spectra show an association. The quality assessment of the commercial ultra-diluted organic drugs obtained from natural products may be initiated by monitoring in vivo studies on animal models.

Interaction of β-casomorphins with multiple opioid receptors: In vitro and in vivo studies in the newborn rat brain

1986 ◽  
Vol 30 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Andrea Volterra ◽  
Patrizia Restani ◽  
Nicoletta Brunello ◽  
Corrado L. Galli ◽  
Giorgio Racagni
Keyword(s):  
Rat Brain ◽  
Opioid Receptors ◽  
In Vivo Studies ◽  
Newborn Rat
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