Fritsche C, Schwartz J H
Am J Physiol. 1985 Dec;249(6 Pt 2):F858-62. doi: 10.1152/ajprenal.1985.249.6.F858.
The turtle bladder consists primarily of two mucosal cell types, mitochondrial rich (MR) and granular (G) cells. The MR cells secrete H+. In addition, the bladder secretes HCO3-, an energy-requiring Cl(-)-dependent transport system. These studies were designed to identify the cell type responsible for HCO3- secretion. Specific HCO3- and H+ secretory inhibitors were added to alter O2 consumption of MR and G cells. Cells were separated by Ficoll density centrifugation. Ouabain (10(-4) M) was used in all studies to eliminate O2 consumption associated with Na+ transport. O2 consumption of cells treated with 10(-4) M 4-acetamido-4'-isothiocyanostilbene-2,2'-sulfonic acid (SITS), which indirectly inhibits H+ secretion, was compared with cells additionally treated with 5 X 10(-4) M acetazolamide, an inhibitor of both H+ and HCO3- secretion. O2 consumption of MR cells treated with SITS alone was significantly greater than that of MR cells additionally treated with acetazolamide (delta = 0.56 +/- 0.10 microliter O2 X h-1 X mg protein-1, n = 6, P less than 0.003). There was no significant difference in G cells similarly treated. Another means of selectively altering H+ and HCO3- transports and their associated metabolic rates is to manipulate the Cl- concentration of the incubation medium. In a Cl(-)-rich medium, HCO3- and H+ transports are maximized. In low Cl(-)-SO2-4 medium, HCO3- secretion is selectively reduced.(ABSTRACT TRUNCATED AT 250 WORDS)
龟膀胱主要由两种黏膜细胞类型组成，即富含线粒体（MR）的细胞和颗粒（G）细胞。MR细胞分泌H⁺。此外，膀胱还分泌HCO₃⁻，这是一种需要能量的Cl⁻依赖性转运系统。这些研究旨在确定负责HCO₃⁻分泌的细胞类型。添加特定的HCO₃⁻和H⁺分泌抑制剂以改变MR细胞和G细胞的耗氧量。通过Ficoll密度离心分离细胞。在所有研究中均使用哇巴因（10⁻⁴ M）来消除与Na⁺转运相关的耗氧量。将用10⁻⁴ M 4-乙酰氨基-4'-异硫氰基芪-2,2'-二磺酸（SITS）处理的细胞的耗氧量进行比较，SITS间接抑制H⁺分泌，另外还用5×10⁻⁴ M乙酰唑胺处理细胞，乙酰唑胺是H⁺和HCO₃⁻分泌的抑制剂。单独用SITS处理的MR细胞的耗氧量显著高于另外用乙酰唑胺处理的MR细胞（差值 = 0.56±0.10微升O₂×小时⁻¹×毫克蛋白⁻¹，n = 6，P＜0.003）。类似处理的G细胞没有显著差异。另一种选择性改变H⁺和HCO₃⁻转运及其相关代谢率的方法是操纵孵育培养基的Cl⁻浓度。在富含Cl⁻的培养基中，HCO₃⁻和H⁺转运最大化。在低Cl⁻-SO₄²⁻培养基中，HCO₃⁻分泌被选择性降低。（摘要截短于250字）
