McConalogue K, Furness J B
Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Australia.
Cell Tissue Res. 1996 Jun;284(3):367-72. doi: 10.1007/s004410050597.
Calretinin is a calcium-binding protein which occurs in neurons and endocrine cells, including neurons throughout the gastrointestinal tract. Calretinin-immunoreactive (IR) neurons innervate the circular muscle in the guinea-pig distal colon and have descending as well as ascending projections. This suggests that calretinin-IR is in motor neurons, but whether it might be in excitatory or inhibitory motor neurons or both was previously undetermined. The presence of calretinin-IR in neurons innervating the taenia coli has not been previously reported. Numerous fibres in the circular muscle of the distal colon and in the taenia coli displayed immunoreactivity for calretinin. Tachykinin (TK), vasoactive intestinal peptide (VIP), calretinin, and gamma-aminobutyric acid (GABA) immunoreactivity was also in fibres innervating these targets. The abundances of these fibres was estimated to be TK > VIP > calretinin > GABA. Double label immunohistochemistry revealed the presence in both tissues of populations of calretinin-IR fibres which were also TK-IR, and fibres with calretinin and GABA-IR in the colon, but calretinin-IR fibres were never VIP-IR. TK- and VIP-IR were in separate populations of nerve fibres as were GABA- and TK-IR. It is concluded that calretinin-IR does not provide a definitive labelling of a physiologically known subgroup of motor neurons, either in the distal colon or in the taenia coli, but that calretinin is most likely to be in excitatory motor neurons.
钙视网膜蛋白是一种钙结合蛋白，存在于神经元和内分泌细胞中，包括整个胃肠道的神经元。钙视网膜蛋白免疫反应性（IR）神经元支配豚鼠远端结肠的环形肌，并具有下行和上行投射。这表明钙视网膜蛋白IR存在于运动神经元中，但它是存在于兴奋性运动神经元、抑制性运动神经元还是两者中，此前尚未确定。此前尚未报道支配结肠带的神经元中存在钙视网膜蛋白IR。远端结肠环形肌和结肠带中的许多纤维显示出对钙视网膜蛋白的免疫反应性。速激肽（TK）、血管活性肠肽（VIP）、钙视网膜蛋白和γ-氨基丁酸（GABA）免疫反应性也存在于支配这些靶标的纤维中。估计这些纤维的丰度为TK>VIP>钙视网膜蛋白>GABA。双重标记免疫组织化学显示，在这两种组织中均存在同时为TK-IR的钙视网膜蛋白IR纤维群体，以及结肠中同时具有钙视网膜蛋白和GABA-IR的纤维，但钙视网膜蛋白IR纤维从未为VIP-IR。TK-IR和VIP-IR存在于不同的神经纤维群体中，GABA-IR和TK-IR也是如此。结论是，钙视网膜蛋白IR不能明确标记远端结肠或结肠带中生理上已知的运动神经元亚组，但钙视网膜蛋白很可能存在于兴奋性运动神经元中。
