Andersen B L, Tarpley H T, Regen D M
Biochim Biophys Acta. 1978 Apr 20;508(3):525-38. doi: 10.1016/0005-2736(78)90097-4.
A method was developed for study of beta-hydroxybutyrate transport in erythrocytes and thymocytes. Critical to the method was a centrifugal separation of cells from medium which took advantage of beta-hydroxybutyrate transport's temperature dependence and inhibition by phloretin and methylisobutylxanthine, all of which are demonstrated in this work. These properies suggested mediated transport, as did saturation kinetics and inhibition by several agents including pyruvate and alpha-cyanocinnamate. Most conclusive in this regard was a 2-fold preference for D- over L-beta-hydroxybutyrate. Entry was not Na+ dependent. It was stimulated by substitution of SO2-4 for most of the Cl-. The equilibrium beta-hydroxybutyrate space was much higher than the Cl- space of thymocytes, suggesting that beta-hydroxybutyrate entry is not associated with net inward negative current and is not coupled to outward Cl- or inward K+ movement (assuming that K+ is at elecrochemical equilibrium). Coupling to H+ entry or OH- exit is compatible with the result. These findings are consistent with beta-hydroxybutyrate entry by the carboxylate transport site which has been studied extensively with pyruvate and lactate as permeants. The Cl-/HCO-3 exchange carrier did not appear to contribute significantly to beta-hydroxybutyrate transport.
开发了一种用于研究红细胞和胸腺细胞中β-羟基丁酸转运的方法。该方法的关键是利用β-羟基丁酸转运对温度的依赖性以及根皮素和甲基异丁基黄嘌呤对其的抑制作用，通过离心将细胞与培养基分离，本研究中均证实了这些特性。这些特性表明存在介导转运，饱和动力学以及包括丙酮酸和α-氰基肉桂酸在内的几种试剂的抑制作用也表明了这一点。在这方面最具决定性的是对D-β-羟基丁酸的偏好是L-β-羟基丁酸的2倍。进入不依赖于Na +。用大部分SO2-4替代Cl-可刺激进入。平衡时β-羟基丁酸的空间远高于胸腺细胞的Cl-空间，这表明β-羟基丁酸的进入与内向净负电流无关，并且不与外向Cl-或内向K +移动偶联（假设K +处于电化学平衡）。与H +进入或OH-流出偶联与结果相符。这些发现与通过羧酸盐转运位点进入β-羟基丁酸一致，该位点已用丙酮酸和乳酸作为渗透剂进行了广泛研究。Cl-/HCO-3交换载体似乎对β-羟基丁酸转运没有显著贡献。
