Anti-Obesity Actions of Mastication Driven by Histamine Neurons in Rats

Abstract

Implications of mastication in energy intake and expenditure regulated by histamine (HA) neurons were investigated in rats. Depletion of neuronal HA from the mesencephalic trigeminal sensory nucleus (Me5) reduced eating speed, but that from a satiety center of the ventromedial hypothalamus (VMH) increased both meal size and its duration leaving eating speed unaffected. Turnover of neuronal HA in the Me5 was elevated at the early phase of feeding and that in the VMH was at the later phase. This elevated turnover was abolished by gastric intubations of an isocaloric liquid diet or an equivolume of water. Mastication-induced activation of HA neurons suppressed physiological food intake through H1-receptor in the hypothalamic paraventricular nucleus (PVN) and the VMH. On the other hand, the HA neurons activation accelerated lipolysis particularly in the visceral adipose tissues and up-regulated mRNA expression of uncoupling protein family through sympathetic efferent nerve. Mastication thus plays an important role as a potent input signal to activate HA neurons. Our recent findings have evidently shown how tightly and elegantly HA neurons are concordant with leptin signaling system through a negative feedback loop.

Impact of eating rate on obesity and cardiovascular risk factors according to glucose tolerance status: the Fukuoka Diabetes Registry and the Hisayama Study

“…Decreased mastication in fast eaters and subsequent inactivation of neuronal histamine may be related to weight gain. Mastication-induced activation of histamine neurons suppresses physiological food intake through H 1 -receptors in the hypothalamic paraventricular nucleus and the ventromedial hypothalamic nucleus, known as satiety centres [27]. In addition, histamine neuron activation increases energy expenditure by upregulating gene expression of the uncoupling protein family through the sympathetic efferent nerve, leading to accelerated lipolysis, particularly in visceral adipose tissue, in rats [27].…”

Masticatory function and cognitive function

“…Mastication also suppresses the increase in plasma interleukin-1beta, interleukin-6 and leptin levels that occur during stress 73) . Masticatory function may involve inactivation of histamine neurons through the ventromedial hypothalamus and the mesencephalic trigeminal sensory nucleus 75) . The histamine system may contribute to modulate of the activity of the septohippocampal cholinergic system 76) .…”

Effects of appetite, BMI, food form and flavor on mastication: almonds as a test food

“…Oral feeding is more effective at inducing satiety than intragastric infusions, suggesting that oral stimulation optimizes the development of satiety (Jordan, 1969;Lavin et al, 2002). Studies in rats suggest that mastication activates histaminergic neurons in the paraventricular nucleus and ventromedial hypothalamus (Sakata et al, 2003). Activation of these neurons is linked with decreased food intake in rats, while antagonists augment intake (Sakata et al, 1988a, b;Fukagawa et al, 1989;Ookuma et al, 1989Ookuma et al, , 1993Sakata, 1995).…”