Journal ArticleDOI
Effect of adrenalectomy and corticosterone substitution on glucose and glycogen metabolism in rat brain.
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TLDR
Investigation of whether or not adrenalectomy (ADX) and glucocorticoid substitution influence the pathway of both glucose and glycogen metabolism in cerebral parietotemporal cortex and hippocampus found that the effect of ADX on enzyme activities was reversed.Abstract:
In non-nervous tissues, glucocorticoids (GCs) counteract the effects of insulin and stimulate gluconeogenesis. The present study was designed to investigate whether or not adrenalectomy (ADX) and glucocorticoid substitution influence the pathway of both glucose and glycogen metabolism in cerebral parietotemporal cortex and hippocampus, and if so how. The activities of respective key enzymes, such as hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), glucose-6-phosphatase (G6Pase) and phosphorylase a (PLa), and the concentrations of the intermediates, such as glucose (Glu), glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), fructose-1,6-bisphosphate (F16PP), pyruvate (Pyr), lactate (Lac), glycogen (Glyc) and glucose-1-phosphate (G1F), were measured in the brains of 1-year-old male Wistar rats under controlled conditions 3 days after ADX or sham operation and in a pilot study after ADX and substitution with corticosterone (CST) suspended in sesame oil or after ADX and subcutaneous administration of the vehicle only. An increase in both glycolytic flux and glycogen breakdown and a decrease in gluconeogenesis in cerebral cortex but not in hippocampus were observed after ADX. After substitution with CST in adrenalectomized rats the effect of ADX on enzyme activities was reversed: significant differences from adrenalectomized rats that received vehicle only was shown for PK and G6Pase activities in both areas of the rat brain investigated.read more
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Actions of glucocorticoids at a seasonal baseline as compared to stress-related levels in the regulation of periodic life processes.
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The human stress response.
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Brain glucose and energy metabolism abnormalities in sporadic Alzheimer disease. Causes and consequences: an update.
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References
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Journal Article
Protein Measurement with the Folin Phenol Reagent
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
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Two Receptor Systems for Corticosterone in Rat Brain: Microdistribution and Differential Occupation
TL;DR: It is concluded that CORT action via CR may be involved in a tonic (permissive) influence on brain function with the septohippocampal complex as a primary target.
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The Neuroendocrinology of Stress and Aging: The Glucocorticoid Cascade Hypothesis*
TL;DR: The goal in the study of aging is not to halt the aging process, because we can no more be cured of aging than of birth as mentioned in this paper, but to slow and soften the sharpest edges of the biological unraveling that constitutes aging.
Journal Article
The Neuroendocrinology of Stress and Aging: The Glucocorticoid Cascade Hypothesis
TL;DR: The goal in the study of aging is not to halt the process, because the authors can no more be cured of aging than of birth, but to slow and soften the sharpest edges of the biological unraveling that constitutes aging.
Journal ArticleDOI
Prolonged glucocorticoid exposure reduces hippocampal neuron number: implications for aging
TL;DR: The hypothesis that cumulative exposure to corticosterone over the lifespan may contribute to age-related loss of neurons in the hippocampus is supported, and that prolonged stress or exposure to CORT accelerates this process of cell loss.