Fulltext:
50266.pdf
Embargo:
until further notice
Size:
153.8Kb
Format:
PDF
Description:
Publisher’s version
Publication year
2006Source
Medical Hypotheses, 67, 5, (2006), pp. 1213-22ISSN
Publication type
Article / Letter to editor
Display more detailsDisplay less details
Organization
Medical Microbiology
Medical Oncology
Journal title
Medical Hypotheses
Volume
vol. 67
Issue
iss. 5
Page start
p. 1213
Page end
p. 22
Subject
EBP 4: Quality of Care; NCEBP 7: Effective primary care and public health; NCMLS 1: Immunity, infection and tissue repair; UMCN 1.1: Functional Imaging; UMCN 1.5: Interventional oncology; UMCN 4.1: Microbial pathogenesis and host defenseAbstract
A review-based hypothesis is presented on the energy flow in cancer patients. This hypothesis centres on the hypoxic condition of tumours, the essential metabolic consequences, especially the gluconeogenesis, the adaptation of the body, and the pathogenesis of cancer cachexia. In growing tumours the O(2) concentration is critically low. Mammalian cells need O(2) for the efficient oxidative dissimilation of sugars and fatty acids, which gives 38 and 128 moles of ATP per mole glucose and palmitic acid, respectively. In the absence of sufficient O(2) they have to switch to anaerobic dissimilation, with only 2 moles of ATP and 2 moles of lactic acid from 1 mole of glucose. Since mammalian cells cannot ferment fatty acids, in vivo tumour cells completely depend on glucose fermentation. Therefore, growth of these tumour cells will require about 40 times more glucose than it should require in the presence of sufficient O(2). Since lactic acid lowers the intracellular pH, it decreases the activity of pyruvate dehydrogenase, stimulates fermentation, and thus amplifies its own fermentative production. Compensatory glucose is provided by hepatic gluconeogenesis from lactic acid. However, the liver must invest 3 times more energy to synthesize glucose than can be extracted by tumour cells in an anaerobic way. The liver extracts the required energy from amino acids and especially from fatty acids in an oxidative way. This may account for weight loss, even when food intake seems adequate. In the liver 6 moles of ATP are invested in the gluconeogenesis of one mole of glucose. The energy content of 4 out of these 6 moles of ATP is dissipated as heat. This may account for the elevated body temperature and sweating experience by cancer patients.
This item appears in the following Collection(s)
- Academic publications [245263]
- Electronic publications [132514]
- Faculty of Medical Sciences [93208]
Upload full text
Use your RU credentials (u/z-number and password) to log in with SURFconext to upload a file for processing by the repository team.