Gabriella M G, Menghi G
Department of Molecular, Cellular and Animal Biology, University of Camerino, Italy.
J Anat. 1994 Oct;185 ( Pt 2)(Pt 2):405-14.
As part of a more extensive study into the involvement of carbonic anhydrase in avian excretory function, the occurrence and distribution of this enzyme was investigated in the quail integrative segment. The integrative segment represents, in birds, that part of the intestinal tract where ureteral urine undergoes postrenal modification to form definitive urine. To define the structural peculiarities within the intestinal epithelium, the constituent parts, namely cloaca, rectum and caecum, as well as the posterior ileum, were examined histochemically to visualise complex carbohydrates. The histochemical findings for carbonic anhydrase activity were compared with the results from a correlative immunohistochemical approach performed with a specific antiserum to avian CA II. Most of the enzyme activity unhomogeneously distributed in the intestinal enterocytes within the mucosal epithelium, was shown to be due to the cytosolic isoenzyme CA II. Additional carbonic anhydrase isoenzymes, distinct from CA II, seem to occur both at the enterocyte brush border and at the smooth muscle layer of the muscularis externa.
作为对碳酸酐酶参与鸟类排泄功能的更广泛研究的一部分，在鹌鹑的整合段对该酶的存在和分布进行了研究。在鸟类中，整合段代表肠道中输尿管尿液进行肾后修饰以形成终尿的部分。为了确定肠上皮内的结构特点，对组成部分，即泄殖腔、直肠和盲肠以及回肠后部进行了组织化学检查，以观察复合碳水化合物。将碳酸酐酶活性的组织化学结果与用针对鸟类CA II的特异性抗血清进行的相关免疫组织化学方法的结果进行了比较。大部分不均匀分布在黏膜上皮内肠上皮细胞中的酶活性被证明是由于胞质同工酶CA II。与CA II不同的其他碳酸酐酶同工酶似乎在肠上皮细胞刷状缘和外肌层的平滑肌层中都有出现。
