Samarzija I, Molnar V, Frömter E
Proc Eur Dial Transplant Assoc. 1983;19:779-83.
Proximal tubular cell membrane potentials were measured in rat kidney in vivo and the response to luminal perfusion of 2mmolar phosphate (Pi) was studied. Pi transport was preferentially rheogenic at low pH (cotransport of 1H2PO2- plus 2Na+) but preferentially electroneutral at high pH (cotransport of 1HPO4--plus 2Na+). The potential response as a function of pH conformed to a model which transports both H2PO4- and HPO4--indiscriminately and whose maximal transport capacity increases with increasing pH. Further kinetic experiments are required to definitely exclude separate transport systems for both ionised forms. Hypercapnic phosphaturia may be explained by a decreased maximal transport capacity of Pi at low luminal pH.
在大鼠肾脏活体中测量近端肾小管细胞膜电位，并研究了向管腔灌注2毫摩尔磷酸盐（Pi）的反应。在低pH值时，Pi转运优先产生电流（1个H2PO4-与2个Na+共转运），而在高pH值时优先呈电中性（1个HPO42-与2个Na+共转运）。作为pH函数的电位反应符合一个模型，该模型不加区分地转运H2PO4-和HPO42-，且其最大转运能力随pH升高而增加。需要进一步的动力学实验来明确排除两种离子化形式的单独转运系统。高碳酸血症性磷酸盐尿可能是由于管腔低pH值时Pi的最大转运能力降低所致。
