Bidmon H J, Stumpf W E
Institute for Neuroanatomy, Heinrich-Heine University of Düsseldorf, Germany.
Histochem J. 1995 Jul;27(7):516-23.
Receptor autoradiography was used for the demonstration of specific binding of the tritiated steroid hormone 1,25-dihydroxyvitamin D3 in the eyes and associated tissues of Anolis carolinensis. A 100-fold excess of non-labelled 1,25-dihydroxyvitamin D3 abolished specific nuclear binding of tracer. Nuclear [3H]-1,25-dihydroxyvitamin D3 binding was present in all animals in the retina stratum ganglionare and stratum nuclear externum as well as in the cornea; however, binding was absent in the optic nerve, except in cells of the surrounding arachnoidea. Additional cranial tissues such as chondrocytes in the sclera, parasphenoid, skeletal muscle cells, and epithelial cells of the lacrimal and Harderian glands exhibited nuclear labelling. The results suggest that 1,25-dihydroxyvitamin D3 has genomic regulatory actions that involve cell proliferation, differentiation, and functions of certain cells of the eye and associated cranial tissues. The presence of vitamin D receptors in tissues of the eye and skeletal muscle in the reptile is in part different from that observed in mammals. In general, receptors for vitamin D and related target tissues appear to be even more extensive in lizards than has been observed in rodents, which may reflect a more extensive dependency of these tissues on solar environment and active seasonal and circadian regulation.
采用受体放射自显影技术，在卡罗来纳安乐蜥的眼睛及相关组织中，对氚标记的类固醇激素1,25 - 二羟基维生素D3的特异性结合进行了示踪。加入100倍过量的未标记1,25 - 二羟基维生素D3可消除示踪剂的特异性核结合。在所有动物的视网膜神经节细胞层、外核层以及角膜中均存在核[3H]-1,25 - 二羟基维生素D3结合；然而，除了周围蛛网膜细胞外，视神经中不存在结合。其他颅部组织，如巩膜、副蝶骨中的软骨细胞、骨骼肌细胞以及泪腺和哈德氏腺的上皮细胞均显示有核标记。结果表明，1,25 - 二羟基维生素D3具有基因组调节作用，涉及眼睛及相关颅部组织某些细胞的增殖、分化和功能。爬行动物眼睛和骨骼肌组织中维生素D受体的存在情况，部分不同于在哺乳动物中观察到的情况。一般来说，蜥蜴体内维生素D及其相关靶组织的受体似乎比在啮齿动物中观察到的更为广泛，这可能反映出这些组织对太阳环境以及活跃的季节性和昼夜节律调节有更广泛的依赖性。
