A theoretical study of electronic factors affecting hydroxylation by model ferryl complexes of cytochrome P-450 and horseradish peroxidase

1999 ◽  
pp. 399-410 ◽  
Author(s):  
Michael Filatov ◽  
Nathan Harris ◽  
Sason Shaik
Keyword(s):  
Horseradish Peroxidase ◽  
Theoretical Study ◽  
Factors Affecting ◽  
Cytochrome P 450

scholarly journals Horseradish peroxidase: factors affecting its distribution after retrograde infusion into the rat parotid gland.

1985 ◽  
Vol 33 (9) ◽  
pp. 942-950 ◽  
Author(s):  
M R Mazariegos ◽  
A R Hand
Keyword(s):  
Horseradish Peroxidase ◽  
Parotid Gland ◽  
Tight Junctions ◽  
Product Inhibition ◽  
Adrenergic Stimulation ◽  
Immunofluorescent Localization ◽  
Cytoplasmic Staining ◽  
Factors Affecting ◽  
Rat Parotid Gland ◽  
Rat Parotid

Previous studies have shown that tight junctions of the unstimulated rat parotid gland are impermeable to retrogradely administered tracers such as myoglobin. Permeability is increased following beta-adrenergic stimulation, allowing the tracers to reach the intercellular and interstitial spaces. Reaction product of retrogradely infused horseradish peroxidase (HRP) and lactoperoxidase in found in the intercellular and interstitial spaces in both resting and stimulated glands, and many acinar and duct cells contain diffuse cytoplasmic reaction product. In this study we investigate several factors that might influence the distribution of HRP in the parotid gland. Tracer distribution was similar with HRP obtained from different suppliers, with different HRP preparations (Sigma types II, VI, VIII, and IX), and at HRP concentrations of 0.1-10 mg/ml. Inclusion of various saccharides in the infusion solution had no effect on the distribution of reaction product. Inhibition of the enzymatic activity of HRP by extraction of the heme group or reaction with hydrazine reduced but did not eliminate the extraluminal and cytoplasmic reaction product. In contrast, HRP treated with high H2O2 concentrations (0.04 M) was retained in the lumina and cytoplasmic staining was nearly abolished. Immunofluorescent localization of untreated and H2O2-treated HRP after retrograde infusion confirmed the findings obtained using diaminobenzidine procedures. These results suggest that the peroxidatic activity of HRP may damage cell membranes and tight junctions in the rat parotid gland, and indicate that permeability studies employing HRP as a tracer should be interpreted with caution.

A theoretical study on the metabolic activation of paracetamol by cytochrome P-450: indications for a uniform oxidation mechanism

1989 ◽  
Vol 2 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Luc Koymans ◽  
Joop H. Van Lenthe ◽  
Ronald Van de Straat ◽  
Gabrielle M. Donne-Op den Kelder ◽  
Nico P. E. Vermeulen
Keyword(s):  
Theoretical Study ◽  
Oxidation Mechanism ◽  
Metabolic Activation ◽  
Cytochrome P 450

Understanding pulmonary gas exchange: ventilation-perfusion relationships

2004 ◽  
Vol 287 (6) ◽  
pp. L1071-L1072 ◽  
Author(s):  
John B. West
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Theoretical Study ◽  
Pulmonary Gas Exchange ◽  
Alveolar Air ◽  
Factors Affecting ◽  
Historical Significance ◽  
Partial Pressures ◽  
Classic Papers

This essay looks at the historical significance of four APS classic papers that are freely available online: Fenn WO, Rahn H, and OTIS AB. A theoretical study of the composition of the alveolar air at altitude. Am J Physiol 146: 637-653. 1946 ( http://ajplegacy.physiology.org/cgi/reprint/146/5/637 ). Rahn H. A concept of mean alveolar air and the ventilation-bloodflow relationships during pulmonary gas exchange. Am J Physiol 158: 21-30, 1949 ( http://ajplegacy.physiology.org/cgi/reprint/158/1/21) ). Riley RL. And Cournand A. "Ideal" Alveolar air and the analysis of ventilation-perfusion relationships in the lungs. J Appl Physiol 1: 825-847. 1949 ( http://jap.physiology.org/cgi/reprint/1/12/825) . Riley RL. And Cournand A. Analysis of factors affecting partial pressures of oxygen and carbon dioxide in gas and blood of lungs: theory. J Appl Physiol 4: 77-101. 1951 ( http://jap.physiology.org/cgi/reprint/4/2/77) .

scholarly journals Social Media and E-Commerce: A Theoretical Study of Factors Affecting Consumer Behavior of Social Media Buyers

2021 ◽  
pp. 71-76
Author(s):  
Dr. Kavita Chauhan ◽  
Faiz Rehman Abbasi
Keyword(s):  
Social Media ◽  
Theoretical Study ◽  
Computer Interface ◽  
Factors Affecting ◽  
Social Media Networks ◽  
Retail Business ◽  
Different Types ◽  
Mobile Channels ◽  
And Behavior ◽  
Attitudes And Behavior

This research studies the factors that impact the behavior of the consumers of social media buyers. The retail business has changed radically over the most recent two decades, at first with the landing of computer-interface shopping and, more recently, with the emerging of mobile channels and social media stages. It is hard for e-commerce or e-retail companies to identify and influence the variables that drive consumers' attitudes and behavior. Different types of media affect people's conclusions, significantly depending on how much time they spend on such media. Facebook and Twitter are two examples of relatively older types of social media in correlation with newer social media networks, for example, Instagram. Furthermore, people use each type of social media for different purposes and based on their individual preferences.

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