Fiorica-Howells Elena, Hen Rene, Gingrich Jay, Li Zhishan, Gershon Michael D
Department of Anatomy and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA.
Am J Physiol Gastrointest Liver Physiol. 2002 May;282(5):G877-93. doi: 10.1152/ajpgi.00435.2001.
The distribution and function of the 5-hydroxytryptamine (5-HT(2A)) receptor were investigated in the intestines of wild-type (5-HT(2A) +/+) and knockout (5-HT(2A) -/-) mice. In 5-HT(2A) +/+ mice, rats, and guinea pigs, 5-HT(2A) receptor immunoreactivity was found on circular and longitudinal smooth muscle cells, neurons, enterocytes, and Paneth cells. Muscular 5-HT(2A) receptors were concentrated in caveolae; neuronal 5-HT(2A) receptors were found intracellularly and on the plasma membranes of nerve cell bodies and axons. Neuronal 5-HT(2A) immunoreactivity was detected as early as E14 in ganglia, intravillus nerves, and the deep muscle plexus. The 5-HT(2A) -/- colon did not express 5-HT(2A) receptors and did not contract in response to exogenous 5-HT. 5-HT(2A) -/- enterocytes were smaller, Paneth cells fewer, and muscle layers thinner (and showed degeneration) compared with those of 5-HT(2A) +/+ littermates. The 5-HT(2A) receptor may thus be required for the maintenance and/or development of enteric neuroeffectors and other enteric functions, although gastrointestinal and colonic transit times in 5-HT(2A) -/- and +/+ mice did not differ significantly.
在野生型（5-HT(2A) +/+）和基因敲除型（5-HT(2A) -/-）小鼠的肠道中，对5-羟色胺（5-HT(2A)）受体的分布和功能进行了研究。在5-HT(2A) +/+小鼠、大鼠和豚鼠中，在环形和纵行平滑肌细胞、神经元、肠上皮细胞和潘氏细胞上发现了5-HT(2A)受体免疫反应性。肌肉中的5-HT(2A)受体集中在小窝中；神经元中的5-HT(2A)受体存在于细胞内以及神经细胞体和轴突的质膜上。早在胚胎第14天，在神经节、绒毛内神经和深部肌肉丛中就检测到了神经元5-HT(2A)免疫反应性。5-HT(2A) -/-结肠不表达5-HT(2A)受体，对外源性5-HT不产生收缩反应。与5-HT(2A) +/+同窝小鼠相比，5-HT(2A) -/-肠上皮细胞较小，潘氏细胞较少，肌肉层较薄（且显示退变）。因此，5-HT(2A)受体可能是维持和/或发育肠神经效应器及其他肠道功能所必需的，尽管5-HT(2A) -/-和 +/+小鼠的胃肠和结肠转运时间没有显著差异。
