自主神经系统调节成年雄性大鼠胰岛β细胞的增殖。
The autonomic nervous system regulates pancreatic β-cell proliferation in adult male rats.
机构信息
Montreal Diabetes Research Center , Montreal, Quebec , Canada.
CRCHUM, Montreal, Quebec , Canada.
出版信息
Am J Physiol Endocrinol Metab. 2019 Aug 1;317(2):E234-E243. doi: 10.1152/ajpendo.00385.2018. Epub 2019 Apr 23.
The pancreatic β-cell responds to changes in the nutrient environment to maintain glucose homeostasis by adapting its function and mass. Nutrients can act directly on the β-cell and also indirectly through the brain via autonomic nerves innervating islets. Despite the importance of the brain-islet axis in insulin secretion, relatively little is known regarding its involvement in β-cell proliferation. We previously demonstrated that prolonged infusions of nutrients in rats provoke a dramatic increase in β-cell proliferation in part because of the direct action of nutrients. Here, we addressed the contribution of the autonomic nervous system. In isolated islets, muscarinic stimulation increased, whereas adrenergic stimulation decreased, glucose-induced β-cell proliferation. Blocking α-adrenergic receptors reversed the effect of epinephrine on glucose + nonesterified fatty acids (NEFA)-induced β-cell proliferation, whereas activation of β-adrenergic receptors was without effect. Infusion of glucose + NEFA toward the brain stimulated β-cell proliferation, and this effect was abrogated following celiac vagotomy. The increase in β-cell proliferation following peripheral infusions of glucose + NEFA was not inhibited by vagotomy or atropine treatment but was blocked by coinfusion of epinephrine. We conclude that β-cell proliferation is stimulated by parasympathetic and inhibited by sympathetic signals. Whereas glucose + NEFA in the brain stimulates β-cell proliferation through the vagus nerve, β-cell proliferation in response to systemic nutrient excess does not involve parasympathetic signals but may be associated with decreased sympathetic tone.
胰岛β细胞能够响应营养环境的变化,通过调节其功能和数量来维持血糖稳态。营养物质可以直接作用于β细胞,也可以通过自主神经间接作用于胰岛。尽管大脑-胰岛轴在胰岛素分泌中非常重要,但关于它在β细胞增殖中的作用却知之甚少。我们之前的研究表明,在大鼠中长时间输注营养物质会引起β细胞增殖的显著增加,部分原因是营养物质的直接作用。在这里,我们研究了自主神经系统的作用。在分离的胰岛中,乙酰胆碱刺激会增加,而肾上腺素刺激会减少葡萄糖诱导的β细胞增殖。阻断α肾上腺素能受体可逆转肾上腺素对葡萄糖+非酯化脂肪酸(NEFA)诱导的β细胞增殖的作用,而激活β肾上腺素能受体则没有影响。向大脑输注葡萄糖+NEFA 会刺激β细胞增殖,而腹腔神经切断术会消除这种作用。外周输注葡萄糖+NEFA 后β细胞增殖增加,但迷走神经切断术或阿托品处理不能抑制这种增加,而肾上腺素的共输注则可阻断这种增加。我们的结论是,β细胞增殖受到副交感神经和交感神经信号的刺激。虽然大脑中的葡萄糖+NEFA 通过迷走神经刺激β细胞增殖,但全身营养过剩引起的β细胞增殖不涉及副交感神经信号,而是可能与交感神经张力降低有关。