Evidence that nitric oxide modulates food intake in mice
Abstract
Nitric oxide (NO) may be an intercellular modulator within the central nervous system. L-arginine, which results in NO synthesis, increased food intake in mice while the inhibitor of NO synthesis, L-NG -nitro arginine (L-NO Arg) inhibited food intake in food deprived mice. L-arginine, but not D-arginine, partially reversed the inhibitory effect of L-NO Arg on food intake. These findings suggest the possibility that NO may be a physiological modulator of food intake and that the possibility of exploring the utility of L-NO arg in the treatment of obesity should be explored.
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Lipopolysaccharide-induced inflammation increases nitric oxide production in taste buds
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Effect of sodium nitroprusside on feeding behavior, voluntary activity, and cloacal temperature in chicks
2022, Physiology and BehaviorNitric oxide (NO) is a well-known gaseous signaling molecule that is involved in a variety of physiological and pathological processes in vertebrates. The role of NO in physiological responses of birds has been investigated primarily using NOS inhibitors. Therefore, the effect of the absence of NO is well characterized. However, there is little knowledge on the effects of abundant NO in birds, which is the case in birds that have infections. Therefore, the purpose of the present study was to determine if intraperitoneal (IP) and intracerebroventricular (ICV) injections of sodium nitroprusside (SNP), a NO donor, affected feed intake, voluntary activity, cloacal temperature, crop emptying rate, and blood constituents in domesticated chicks (Gallus gallus) as model birds. We found that both IP and ICV injections of SNP significantly decreased feed intake while there was little effect on voluntary activity. Cloacal temperature was temporarily, but significantly, decreased by both types of injection of SNP. Additionally, both IP and ICV injections of SNP significantly decreased the crop emptying rate. The IP injection of SNP significantly increased the plasma concentrations of NO2/NO3, which are metabolites of NO, and corticosterone, and decreased the plasma glucose concentrations, while the ICV injection had no effect. The IP injection of SNP also showed the tendency to increase the nitrotyrosine level, to increase superoxide dismutase activity, and to decrease catalase activity in the plasma. These results suggest that under specific situations which produce abundant NO such as infection, NO would induce anorexia, hypothermia, inhibition of feed passage, and activation of the hypothalamus-pituitary-adrenal axis in chicks.
Impacts of essential amino acids on energy balance
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Changes in circulating EAA levels, particularly increased branched-chain amino acids (BCAAs), have been reported in obese human and animal models. Alterations in dietary EAA intake result in improvements in fat and weight loss in rodents, and each has its distinct mechanism. For example, leucine deprivation increases energy expenditure, reduces food intake and fat mass, primarily through regulation of the general control nonderepressible 2 (GCN2) and mammalian target of rapamycin (mTOR) signaling. Methionine restriction by 80% decreases fat mass and body weight while developing hyperphagia, primarily through fibroblast growth factor 21 (FGF-21) signaling. Some effects of diets with different protein levels on energy homeostasis are mediated by similar mechanisms. However, reports on the effects and underlying mechanisms of dietary EAA imbalances on human body weight are few, and more investigations are needed in future.
Role of nitric oxide in type 1 diabetes-induced osteoporosis
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Cholecystokinin acts in the dorsomedial hypothalamus of young male rats to suppress appetite in a nitric oxide-dependent manner
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