scholarly journals Conversion of [U-14C]threonine into 14C-labelled amino acids in the brain of thiamin-deficient rats

1975 ◽  
Vol 150 (2) ◽  
pp. 285-295 ◽  
Author(s):  
M K Gaitonde

In confirmation of the findings of Gaitonde et al. (1974), a decrease in the brain concentration of threonine and serine, and an increase in glycine, were observed in rats maintained on a thiamin-deficient diet. Similar changes were found in the blood, and the concentration of several other amino acids in the blood decreased significantly. There was a correlation between the concentrations of threonine, serine, aspartate and asparagine in the brain and blood. In experiments in which [U-14C]threonine was injected into rats most of the radioactivity in the brain and blood of control rats was, as expected, in threonine in the acid soluble metabolites. In contrast, a considerable proportion of radioactivity was also found in other amino acids, namely glutamate, glutamine, aspartate, γ-aminobutyrate and alanine, in the brain of thiamin-deficient rats. [U-14C]Threonine was also converted into 14C-labelled lactate and glucose, but the extent of this conversion was severalfold higher in thiamin-deficient than in control rats. This finding gave evidence of the stimulation in thiamin-deficient rats of the catabolism of [U-14C]threonine to [14C]lactate by the aminoacetone pathway catalysed by threonine dehydrogenase, and into succinate via propionate by the α-oxobutyrate pathway catalysed by threonine dehydratase (deaminase). The measurement of specific radioactivities of glutamate, aspartate and glutamine after injection of [U-14C]threonine, indicated a stimulation of the activities of threonine dehydrogenase and threonine dehydratase (deaminase) in the brain of thiamin-deficient rats. The specific radioactivities of glutamate, asparatate and glutamine int he brain were consistent with an alteration in the metabolism of threonine, mainly in the ‘large’ compartment of the brain of thiamin-deficient rats. The measurement of relative specific radioactivity of proteins after injection of [U-14C]threonine indicated a marked decrease in the synthesis of proteins, mainly in the liver of thiamin-deficient rats.

1968 ◽  
Vol 107 (5) ◽  
pp. 615-623 ◽  
Author(s):  
R. W. Wannemacher ◽  
W. K. Cooper ◽  
M. B. Yatvin

Weanling (23-day-old) rats were fed either on an amino acid-deficient diet (6% of casein, which in effect represents an ‘amino acid-deficient’ diet) or on a diet containing an adequate amount of protein (18% of casein) for 28 days. The hepatic cells from the animals fed on the low-protein diet were characterized by low amino acid content, almost complete inhibition of cell proliferation and a marked decrease in cell volume, protein content and concentration of cytoplasmic RNA compared with cells from control rats. The lower concentration of cytoplasmic RNA was correlated with a decreased ribosomal-RNA content, of which a larger proportion was in the form of free ribosomes. The protein-synthetic competence and messenger-RNA content of isolated ribosomes from liver cells of protein-deprived animals were 40–50% of those noted in controls. At 1hr. after an injection of radioactive uridine, the specific radioactivity of liver total RNA was greater in the group fed on the low-protein diet, but the amount of label that was associated with cytoplasmic RNA or ribosomes was significantly less than that noted in control animals. From these data it was concluded that dietary amino acids regulate hepatic protein synthesis (1) by affecting the ability of polyribosomes to synthesize protein and (2) by influencing the concentration of cytoplasmic ribosomes. It is also tentatively hypothesized that the former process may be directly related to the concentration of cellular free amino acids, whereas the latter could be correlated with the ability of newly synthesized ribosomal sub-units to leave the nucleus.


1960 ◽  
Vol 198 (6) ◽  
pp. 1312-1314 ◽  
Author(s):  
Tatuzi Suzuki ◽  
Elijah B. Romanoff ◽  
Werner P. Koella ◽  
Charles K. Levy

In unanesthetized dogs, adrenal venous blood was collected and its plasma content of 17-hydroxycorticosteroids (17-OHCS) estimated. Electrodes were implanted in the brain stem and electrical stimulation was performed. The location of the electrode tips was verified histologically. After stimulation of the lower posterior hypothalamic area, as well as the lower thalamic area, the adrenal 17-OHCS secretion rate increased markedly. When the upper posterior hypothalamic area, or the area preoptica was stimulated, the slight increase in 17-OHCS secretion rate first observed was followed by a marked decrease below the prestimulation level. Stimulation of the capsula interna produced no response in adrenal cortical secretion.


1972 ◽  
Vol 130 (4) ◽  
pp. 975-981 ◽  
Author(s):  
Ian Pull ◽  
Henry McIlwain

Adenine nucleotides of guinea-pig neocortical tissues were labelled by incubation with [14C]adenine and excess of adenine was then removed by superfusion with precursor-free medium. Adenine derivatives released from the tissue during continued superfusion, including a period of electrical stimulation of the tissue, were collected by adsorption and examined after elution and concentration. The stimulation greatly increased the 14C output, and material collected during and just after stimulation had a u.v. spectrum which indicated adenosine to be a major component. The additional presence of inosine and hypoxanthine was shown by chromatography and adenosine was identified also by using adenosine deaminase. Total adenine derivatives released from the tissue during a 10min period of stimulation were obtained as hypoxanthine, after deamination and hydrolysis of adenosine and inosine, and amounted to 159nmol/g of tissue. This corresponded to the release of approx. 7pmol/g of tissue per applied stimulus. The hypoxanthine sample derived from superfusate hypoxanthine, inosine and adenosine was of similar specific radioactivity to the sample of inosine separated chromatographically, and each was of higher specific radioactivity than the adenine nucleotides obtained by cold-acid extraction of the tissue.


1992 ◽  
Vol 2 (8) ◽  
pp. 1265-1278
Author(s):  
P A Jose ◽  
J R Raymond ◽  
M D Bates ◽  
A Aperia ◽  
R A Felder ◽  
...  

Dopamine is an endogenous catecholamine that modulates many functions including behavior, movement, nerve conduction, hormone synthesis and release, blood pressure, and ion fluxes. Dopamine receptors in the brain have been classically divided into D1 and D2 subtypes, based on pharmacological data. However, molecular biology techniques have identified many more dopamine receptor subtypes. Several of the receptors cloned from the brain correspond to the classically described D1 and D2 receptors. Several D1 receptor subtypes have been cloned (D1A, D1B, and D5) and are each coupled to the stimulation of adenylyl cyclase. The D2 receptor has two isoforms, a shorter form, composed of 415 amino acids, is termed the D2short receptor. The long form, called the D2long receptor, is composed of 444 amino acids; both are coupled to the inhibition of adenylyl cyclase. The D3 and D4 receptors are closely related to, but clearly distinct from, the D2 receptor. They have not yet been linked to adenylyl cyclase activity. Outside of the central nervous system, the peripheral dopamine receptors have been classified into the DA1 and DA2 subtypes, on the basis of synaptic localization. The pharmacological properties of DA1 receptors roughly approximate those of D1 and D5 receptors, whereas those of DA2 receptors approximate those of D2 receptors. A renal dopamine receptor with some pharmacological features of the D2 receptor but not linked to adenylyl cyclase has been described in the renal cortex and inner medulla. In the inner medulla, this D2-like receptor, termed DA2k, is linked to stimulation of prostaglandin E2 production, apparently due to stimulation of phospholipase A2. Of the cloned dopamine receptors, only the mRNA of the D3 receptor has been reported in the kidney. The DA1 receptor in the kidney is associated with renal vasodilation and an increase in electrolyte excretion. The DA1-related vasodilation and inhibition of electrolyte transport is mediated by cAMP. The role of renal DA2 receptors remains to be clarified. Although DA1 and DA2 receptors may act in concert to decrease transport in the renal proximal convoluted tubule, the overall function of DA2 receptors may be actually the opposite of those noted for DA1 receptors. Dopamine has been postulated to act as an intrarenal natriuretic hormone. Moreover, an aberrant renal dopaminergic system may play a role in the pathogenesis of some forms of hypertension. A decreased renal production of dopamine and/or a defective transduction of the dopamine signal is/are present in some animal models of experimental hypertension as well as in some forms of human essential hypertension.


1971 ◽  
Vol 122 (2) ◽  
pp. 135-138 ◽  
Author(s):  
Jill E. Cremer

The metabolism of ketone bodies by rat brain was studied in vivo. Rats starved for 48h were given either d-β-hydroxy[3-14C]butyrate or [3-14C]acetoacetate by intravenous injection and killed after 3 or 10min. Total radioactivity in the acid-soluble material of the brain and the specific radioactivities of the brain amino acids glutamate, glutamine, aspartate and γ-aminobutyrate were determined. A group of fed animals were also given d-β-hydroxy[3-14C]butyrate. In the brains of all animals 14C was present in the acid-soluble material and the specific radioactivity of glutamate was greater than that of glutamine.


1975 ◽  
Vol 20 (12) ◽  
pp. 923-924
Author(s):  
MADGE E. SCHEIBEL ◽  
ARNOLD B. SCHEIBEL

2020 ◽  
Vol 44 (3) ◽  
pp. 241-249
Author(s):  
Yoshiaki Omura

While a visiting Professor at the University of Paris, VI (formerly Sorvonne) more than 40 years ago, the Author became very good friends with Dr. Paul Nogier who periodically gave seminars and workshops in Paris. After the author diagnosed his cervical problem & offered him simple help, Dr. Nogier asked the Author to present lectures and demonstrations on the effects of ear stimulation, namely the effects of acupuncture & electrical stimulation of the ear lobules. It is only now, in 2019 that we have discovered 2–5 minute high frequency stimulation of the ear lobule inhibits cancer activity for 1– 4 hours post stimulation. Although the procedure is extremely simple. First take optimal dose of Vitamin D3, which has the most essential 10 unique beneficial factors required for every human cell activity. Next, apply high frequency stimulation to ear lobule while the worst ear lobule is held by all fingers with vibrator directly touching the surface of the worst ear lobule, preferably after patient repeatedly takes optimal dose of Vitamin D3. When the worst ear lobule is held between thumb & index fingers and applying mechanical stimulation of 250 ~ 500 mechanical vibration/second for 2 ~ 5 minutes using an electrical vibrator, there is rapid disappearance of cancer activity in both the brain and rest of the body for short time duration 1 ~ 4 hours. The effect often increases by additional pressure by holding fingers. As of May 2019, the Author found that many people from various regions of the world developed early stages of multiple cancers. For evaluation of this study, U. S. patented Bi-Digital O-Ring Test (BDORT) was used which was developed by the Author while doing his Graduate experimental physics research at Colombia University. BDORT was found to be most essential for determining the beneficial effects as well as harmful effects of any substance or treatment. Using BDORT, Author was the first to recognize severe increasing mid-backache was an early sign of pancreatic cancer of President of New York State Board of Medicine after top pain specialists failed to detect the cause after 3 years of effort, while the BDORT showed early stages of cancer whereas conventional X-Ray of the pancreas did not show any cancer image until 2 months after Author detected with BDORT. For example, the optimal dose of the banana is usually about 2.0 - 2.5 millimeters cross section of the banana. A whole banana is more than 50 ~ 100 times the optimal dose. Any substance eaten in more than 25 times of its optimal dose becomes highly toxic and creates DNA mutations which can cause multiple malignancies in the presence of strong electro-magnetic field. With standard medication given by doctor, patients often become sick and they are unable to reduce body weight, unless medication is reduced or completely stopped. When the amount of zinc is very high, DNA often becomes unstable and multiple cancers can grow rapidly in the presence of strong electromagnetic field. Large amount of Vitamin C from regular orange or orange juice inhibit the most important Vitamin D3 effects. At least 3 kinds of low Vitamin C oranges will not inhibit Vitamin D3. Since B12 particularly methyl cobalamin which is a red small tablet is known to improve brain circulation very significantly we examined its effect within 20 seconds of oral intake we found the following very significant changes. Acetylcholine in both sides of the brain often increases over 4,500 ng. Longevity gene Sirtuin 1 level increases significantly for short time of few hours. Thymosin α1 and Thymosinβ4 both increase to over 1500 ng from 20 ng or less.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danilo Reymão Moreira ◽  
Ana Carolina Musa Gonçalves Uberti ◽  
Antonio Rafael Quadros Gomes ◽  
Michelli Erica Souza Ferreira ◽  
Aline da Silva Barbosa ◽  
...  

AbstractThe present study aimed to evaluate the effects of dexamethasone on the redox status, parasitemia evolution, and survival rate of Plasmodium berghei-infected mice. Two-hundred and twenty-five mice were infected with Plasmodium berghei and subjected to stimulation or inhibition of NO synthesis. The stimulation of NO synthesis was performed through the administration of L-arginine, while its inhibition was made by the administration of dexamethasone. Inducible NO synthase (iNOS) inhibition by dexamethasone promoted an increase in the survival rate of P. berghei-infected mice, and the data suggested the participation of oxidative stress in the brain as a result of plasmodial infection, as well as the inhibition of brain NO synthesis, which promoted the survival rate of almost 90% of the animals until the 15th day of infection, with possible direct interference of ischemia and reperfusion syndrome, as seen by increased levels of uric acid. Inhibition of brain iNOS by dexamethasone caused a decrease in parasitemia and increased the survival rate of infected animals, suggesting that NO synthesis may stimulate a series of compensatory redox effects that, if overstimulated, may be responsible for the onset of severe forms of malaria.


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