Injection with gold thioglucose impairs sensitivity to glucose: evidence that glucose-responsive neurons are important for long-term regulation of body weight.

It has been proposed, but never demonstrated, that glucose-responsive neurons are essential for the long-term regulation of body weight, and that mice injected with gold-thio-glucose (GTG) become obese due to destruction of glucose-responsive neurons. To assess these hypotheses, mice were injected with either saline (control) or a dose of GTG that produces obesity, and the effects on feeding of peripheral injection of saline, glucose, 2-deoxyglucose (2-DG), or cholecystokinin (CCK) were measured. In control mice, 2-DG increased, whereas glucose and CCK decreased, food intake significantly. In contrast, in GTG-treated mice, 2-DG and glucose did not have a significant effect on food intake. The GTG-treated mice remained sensitive to the inhibitory effect of CCK on food intake. These data indicate that i.p. injection of GTG, which produces obesity, also destroys glucose-responsive neurons, consistent with the hypothesis that glucose-responsive neurons contribute to the long-term regulation of body weight.