Do endogenous and exogenous glucocorticoids decrease plasma ghrelin in humans?
We have shown for the first time that plasma ghrelin levels are decreased under endogenously or exogenously induced hypercortisolism, making ghrelin an unlikely candidate for causing the changes in energy balance or body composition characteristic of Cushing's disease. However, the reduced ghrelin secretion could reflect a compensation mechanism in reaction to the metabolic consequences of chronic hypercortisolism.
In the liver of guinea pig pups, infused peroxides cause oxidation of membrane-derived prostanoids. The decrease in glutathione in response to administration of peroxides suggests consumption rather than a response to a free radical attack. Despite the oxidant load associated with peroxides generated in MVP, the multivitamin preparation protected membranes as the prostanoid ratio, and glutathione levels remained at control levels.