根据[14C]二甲基恶唑烷-2,4-二酮的分布计算促甲状腺素、乙酰唑胺、4-乙酰氨基-4'-异硫氰基芪-2,2'-二磺酸、高氯酸盐、哇巴因和呋塞米对龟甲状腺细胞和管腔液中pH值和HCO3-浓度的影响。

Effects of thyrotropin, acetazolamide, 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid, perchlorate, ouabain and furosemide on pH and HCO3- concentrations in cells and luminal fluid of turtle thyroid as calculated from the distribution of [14C]dimethyloxazolidine-2,4-dione.

作者信息

Chow S Y, Yen-Chow Y C, Woodbury D M

出版信息

J Pharmacol Exp Ther. 1983 Apr;225(1):17-23.

Abstract

[14C]Dimethyloxazolidine-2,4-dione was used to determine the pH and bicarbonate concentration ([HCO3-]) in follicular cells and luminal fluid (LF) of turtle thyroids. Values of cellular and luminal pH and [HCO3-] were derived from the steady-state [14C]dimethyloxazolidine-2,4-dione values in whole gland and in the follicular LF sampled by micropipettes inserted into the follicular lumen and by resolution of the [14C]dimethyloxazolidine-2,4-dione uptake curve into its components by a computer program. In extracellular fluid of control turtles at 24 degrees C, the pH was 7.66, [HCO3-] was 33.1 mmol/l and pCO2 was 33.6 mm Hg. In thyroidal follicular cells, pH was 7.26 and [HCO3-] was 14.3 mmol/l; and in LF, pH was 7.32 and [HCO3-] was 16.5 mmol/l. These data provide evidence that H+ and HCO3- do not distribute according to their electrochemical gradients across both the basal and apical membranes of thyroid. Thyrotropin increased cell pH to 7.70 and [HCO3-] to 39.8 mmol/l; luminal pH and [HCO3-] were also markedly increased. Acetazolamide reduced [HCO3-] in both cells and LF. 4-Acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid increased cellular pH and [HCO3-] but did not alter these parameters in LF. Both ouabain and furosemide increased cellular pH and [HCO3-] and decreased luminal pH and [HCO3-]. Methimazole increased cellular pH and [HCO3-], decreased LF [HCO3-] and did not affect the LF pH.

摘要

用[¹⁴C]二甲基恶唑烷 - 2,4 - 二酮来测定龟甲状腺滤泡细胞和管腔液（LF）中的pH值和碳酸氢盐浓度（[HCO₃⁻]）。细胞内和管腔的pH值以及[HCO₃⁻]值是根据全腺中以及通过插入滤泡腔的微量移液器所采集的滤泡LF中的稳态[¹⁴C]二甲基恶唑烷 - 2,4 - 二酮值，并通过计算机程序将[¹⁴C]二甲基恶唑烷 - 2,4 - 二酮摄取曲线分解为其各个成分而得出的。在24℃的对照龟的细胞外液中，pH为7.66，[HCO₃⁻]为33.1 mmol/L，pCO₂为33.6 mmHg。在甲状腺滤泡细胞中，pH为7.26，[HCO₃⁻]为14.3 mmol/L；在管腔液中，pH为7.32，[HCO₃⁻]为16.5 mmol/L。这些数据表明，H⁺和HCO₃⁻并非根据其电化学梯度在甲状腺的基底膜和顶膜之间分布。促甲状腺激素使细胞内pH升高至7.70，[HCO₃⁻]升高至39.8 mmol/L；管腔pH和[HCO₃⁻]也显著升高。乙酰唑胺降低了细胞和管腔液中的[HCO₃⁻]。4 - 乙酰氨基 - 4'- 异硫氰基芪 - 2,2'- 二磺酸升高了细胞内pH和[HCO₃⁻]，但未改变管腔液中的这些参数。哇巴因和呋塞米都升高了细胞内pH和[HCO₃⁻]，并降低了管腔pH和[HCO₃⁻]。甲巯咪唑升高了细胞内pH和[HCO₃⁻]，降低了管腔液中的[HCO₃⁻]，且不影响管腔液pH。