The Role of the Microsomal Membrane in Control of Uridine Diphosphate Glucuronyltransferase Activity in vitro and in vivo

1974 ◽  
Vol 2 (6) ◽  
pp. 1167-1172 ◽  
Author(s):  
A. B. GRAHAM ◽  
D. T. PECHEY ◽  
G. C. WOOD ◽  
B. G. WOODCOCK
Keyword(s):  
Microsomal Membrane ◽  
Uridine Diphosphate

scholarly journals Phenol sulphotransferase and uridine diphosphate glucuronyltransferase from rat liver in vivo and in vitro. 2,6-Dichloro-4-nitrophenol as selective inhibitor of sulphation

1977 ◽  
Vol 165 (3) ◽  
pp. 553-559 ◽  
Author(s):  
Gerard J. Mulder ◽  
Egbert Scholtens
Keyword(s):  
Rat Liver ◽  
Inhibitory Effect ◽  
Selective Inhibitor ◽  
Biological Processes ◽  
Uridine Diphosphate ◽  
Duration Of Action ◽  
Long Duration

Microsomal UDP-glucuronyltransferase and cytosolic sulphotransferase share many substrates, such as phenols and hydroxamic acids. In a search for a selective inhibitor of sulphation, several phenolic compounds were tested. 2,6-Dichloro-4-nitrophenol is introduced as a selective inhibitor of sulphation in vivo, having no effect on UDP-glucuronyltransferase activity. As substrate for both conjugating enzymes the phenolic drug harmol (7-hydroxy-1-methyl-9H-pyrido[3,4-b]indole) was used. In the rat in vivo 2,6-dichloro-4-nitrophenol caused almost complete inhibition of harmol sulphation after a single intraperitoneal injection (26μmol/kg) for 48h; the percentage of harmol sulphated decreased from 75% in controls to 5% in the treated rats. The percentage of harmol glucuronidated increased from 25 to 95%. Pentachlorophenol was equally effective but also highly toxic. Salicylamide had only a very-short-lasting inhibitory effect on sulphation. In vitro, 2,6-dichloro-4-nitrophenol inhibited sulphation of harmol by a rat liver postmitochondrial supernatant completely at 1μm, whereas even at 100μm it had no effect on glucuronidation of harmol. It is concluded that 2,6-dichloro-4-nitrophenol is a selective inhibitor of sulphation and, further, that its long duration of action makes it suitable for studies on the regulatory role of sulphation in some biological processes.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

Vitamin D as potential therapeutic anticancer agent

2018 ◽  
pp. 1-3
Keyword(s):  
Vitamin D ◽  
Anticancer Activity ◽  
Anticancer Agent ◽  
Antitumor Agents ◽  
Metastatic Potential ◽  
Anticancer Properties ◽  
Chemotherapy Agents

The role of vitamin D is implicated in carcinogenesis through numerous biological processes like induction of apoptosis, modulation of immune system inhibition of inflammation and cell proliferation and promotion of cell differentiation. Its use as additional adjuvant drug with cancer treatment may be novel combination for improved outcome of different cancers. Numerous preclinical, epidemiological and clinical studies support the role of vitamin D as an anticancer agent. Anticancer properties of vitamin D have been studied widely (both in vivo and in vitro) among various cancers and found to have promising results. There are considerable data that indicate synergistic potential of calcitriol and antitumor agents. Possible mechanisms for modulatory anticancer activity of vitamin D include its antiproliferative, prodifferentiating, and anti-angiogenic and apoptic properties. Calcitriol reduces invasiveness and metastatic potential of many cancer cells by inhibiting angiogenesis and regulating expression of the key molecules involved in invasion and metastasis. Anticancer activity of vitamin D is synergistic or additive with the antineoplastic actions of several drugs including cytotoxic chemotherapy agents like paclitaxel, docetaxel, platinum base compounds and mitoxantrone. Benefits of addition of vitamin D should be weighed against the risk of its toxicity.

A Review on Melatonin’s Effects in Cancer: Potential Mechanisms

2018 ◽  
Vol 18 (7) ◽  
pp. 985-992 ◽  
Author(s):  
Aysegul Hanikoglu ◽  
Ertan Kucuksayan ◽  
Rana Cagla Akduman ◽  
Tomris Ozben
Keyword(s):  
Systematic Review ◽  
Antioxidant Activity ◽  
Membrane Receptors ◽  
Cancer Development ◽  
Secretory Product ◽  
Prevention And Treatment ◽  
G Protein Coupled

This systematic review aims to elucidate the role of melatonin (N-acetyl-5-metoxy-tryptamine) (MLT) in the prevention and treatment of cancer. MLT is a pineal gland secretory product, an evolutionarily highly conserved molecule; it is also an antioxidant and an impressive protector of mitochondrial bioenergetic activity. MLT is characterized by an ample range of activities, modulating the physiology and molecular biology of the cell. Its physiological functions relate principally to the interaction of G Protein-Coupled MT1 and MT2 trans-membrane receptors (GPCRs), a family of guanidine triphosphate binding proteins. MLT has been demonstrated to suppress the growth of various tumours both, in vivo and in vitro. In this review, we analyze in depth, the antioxidant activity of melatonin, aiming to illustrate the cancer treatment potential of the molecule, by limiting or reversing the changes occurring during cancer development and growth.

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