Oxygen Economy of Cytochrome P450:  What Is the Origin of the Mixed Functionality as a Dehydrogenase−Oxidase Enzyme Compared with Its Normal Function?

2004 ◽  
Vol 126 (16) ◽  
pp. 5072-5073 ◽  
Author(s):  
Devesh Kumar ◽  
Samuël P. de Visser ◽  
Sason Shaik
2015 ◽  
Vol 34 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Nadja P. Marić ◽  
Slobodanka Pejović Nikolić ◽  
Ivana Buzadžić ◽  
Milica Jovičić ◽  
Sanja Andrić ◽  
...  

Summary The introduction of antipsychotic medication in the 1950s forever changed the outlook on the treatment of schizophrenia, although there is still a large proportion of patients who do not reach functional recovery. At least 30% of patients do not respond to clozapine, the tricyclic dibenzodiazepine with complex pharmacological actions, which was proven to be more effective than any other antipsychotic in the treatment of schizophrenia. According to most of the therapeutic guidelines for schizophrenia, clozapine is the third line therapy for patients who did not respond to other antipsychotics. Large inter-individual variability exists for clozapine bioavailability and plasma steadystate concentrations and clearance. Clozapine is metabolized by the cytochrome P450 oxidase enzyme family (CYP450). Cytochrome P450 1A2 (CYP1A2), which is polymorphically expressed in humans, is the main enzyme of clozapine metabolism. This case report addresses the influence of CYP1A2*1F genetic polymorphism on cloza - pine metabolism, explains the primary non-response of a young patient with schizophrenia due to increased gene expression in homozygous genotype *1F/*1F (increased metabolism of clozapine) and underlies the importance of personalizing schizophrenia treatment by means of genetic and other molecular tools, at least in the cases of »treatment resistance«.


Uro ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 222-227
Author(s):  
Dai D. Nghiem

Tacrolimus is the cornerstone component of all immunosuppressive regimens. Despite its long record of use, very little is known about its acute toxicity syndrome. We describe five patients with acute organ failure, involving both native and transplanted organs, which was reversed by inducing the cytochrome P450-3A system. In all patients, the causative drug was stopped and phenytoin was given intravenously to accelerate tacrolimus metabolism. Within 24 h, tacrolimus trough levels fell daily at a significant level (p < 0.05) and all failed organs recovered their normal function within 48–72 h. Therefore, phenytoin metabolic induction appears to be a safe therapeutic option for patients with acute tacrolimus toxicity.


2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.


2004 ◽  
Vol 71 ◽  
pp. 193-202 ◽  
Author(s):  
David R Brown

Prion diseases, also referred to as transmissible spongiform encephalopathies, are characterized by the deposition of an abnormal isoform of the prion protein in the brain. However, this aggregated, fibrillar, amyloid protein, termed PrPSc, is an altered conformer of a normal brain glycoprotein, PrPc. Understanding the nature of the normal cellular isoform of the prion protein is considered essential to understanding the conversion process that generates PrPSc. To this end much work has focused on elucidation of the normal function and activity of PrPc. Substantial evidence supports the notion that PrPc is a copper-binding protein. In conversion to the abnormal isoform, this Cu-binding activity is lost. Instead, there are some suggestions that the protein might bind other metals such as Mn or Zn. PrPc functions currently under investigation include the possibility that the protein is involved in signal transduction, cell adhesion, Cu transport and resistance to oxidative stress. Of these possibilities, only a role in Cu transport and its action as an antioxidant take into consideration PrPc's Cu-binding capacity. There are also more published data supporting these two functions. There is strong evidence that during the course of prion disease, there is a loss of function of the prion protein. This manifests as a change in metal balance in the brain and other organs and substantial oxidative damage throughout the brain. Thus prions and metals have become tightly linked in the quest to understand the nature of transmissible spongiform encephalopathies.


Xenobiotica ◽  
2009 ◽  
Vol 00 (00) ◽  
pp. 090901052457079-8
Author(s):  
Y. Nishiya ◽  
K. Hagihara ◽  
A. Kurihara ◽  
N. Okudaira ◽  
N.A. Farid ◽  
...  

Xenobiotica ◽  
2009 ◽  
Vol 00 (00) ◽  
pp. 090901052053001-8
Author(s):  
K. Murai ◽  
H. Yamazaki ◽  
K. Nakagawa ◽  
R. Kawai ◽  
T. Kamataki

2015 ◽  
Vol 85 (3-4) ◽  
pp. 129-144 ◽  
Author(s):  
Zahra Heidari ◽  
Awat Feizi ◽  
Leila Azadbakht ◽  
Nizal Sarrafzadegan

Abstract. Background: Minerals are required for the body’s normal function. Aim: The current study assessed the intake distribution of minerals and estimated the prevalence of inadequacy and excess among a representative sample of healthy middle aged and elderly Iranian people. Methods: In this cross-sectional study, the second follow up to the Isfahan Cohort Study (ICS), 1922 generally healthy people aged 40 and older were investigated. Dietary intakes were collected using 24 hour recalls and two or more consecutive food records. Distribution of minerals intake was estimated using traditional (averaging dietary intake days) and National Cancer Institute (NCI) methods, and the results obtained from the two methods, were compared. The prevalence of minerals intake inadequacy or excess was estimated using the estimated average requirement (EAR) cut-point method, the probability approach and the tolerable upper intake levels (UL). Results: There were remarkable differences between values obtained using traditional and NCI methods, particularly in the lower and upper percentiles of the estimated intake distributions. A high prevalence of inadequacy of magnesium (50 - 100 %), calcium (21 - 93 %) and zinc (30 - 55 % for males > 50 years) was observed. Significant gender differences were found regarding inadequate intakes of calcium (21 - 76 % for males vs. 45 - 93 % for females), magnesium (92 % vs. 100 %), iron (0 vs. 15 % for age group 40 - 50 years) and zinc (29 - 55 % vs. 0 %) (all; p < 0.05). Conclusion: Severely imbalanced intakes of magnesium, calcium and zinc were observed among the middle-aged and elderly Iranian population. Nutritional interventions and population-based education to improve healthy diets among the studied population at risk are needed.


2000 ◽  
Vol 86 (5) ◽  
pp. 215-221 ◽  
Author(s):  
Paivi Taavitsainen ◽  
Markku Anttila ◽  
Leena Nyman ◽  
Hari Karnani ◽  
Jarmo S. Salonen ◽  
...  

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