Onsgard-Meyer M, McCoy A L, Knox F G
Department of Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Proc Soc Exp Biol Med. 1996 Nov;213(2):193-5. doi: 10.3181/00379727-213-44050.
Levamisole inhibits alkaline phosphatase (ALP) activity in kidney brush border membranes and increases phosphate excretion in vivo in dogs and rats. I-p-Bromotetramisole (I-BR) is a more potent analog of levamisole in regard to inhibition of ALP activity in vitro, but had no effect on phosphate transport by in vitro proximal tubules of the rabbit. Since its effect on phosphate excretion in vivo has not been studied, the present study tested the effects of infusion of I-BR on phosphate excretion in Sprague-Dawley rats. Fractional excretion of phosphate (FEPi) was measured in thyroparathyroidectomized Sprague-Dawley rats before and during a systemic infusion at 0.8 ml/min of 10 mM I-p-Bromotetramisole oxalate (I-BR, n = 6), or the inactive isomer d-p-Bromotetramisole oxalate (d-BR, n = 5). The FEPi increased significantly from 4.7% +/- 0.9% to 13.4% +/- 3.1% in response to I-BR whereas there were no changes in FEPi with inactive d-BR. In conclusion, systemic infusion of I-p-Bromotetramisole increases FEPi in Sprague-Dawley rats.
左旋咪唑可抑制犬和大鼠肾刷状缘膜中的碱性磷酸酶（ALP）活性，并增加其体内磷酸盐排泄。就体外抑制ALP活性而言，I-p-溴四咪唑（I-BR）是左旋咪唑的一种更有效的类似物，但对兔体外近端小管的磷酸盐转运没有影响。由于尚未研究其对体内磷酸盐排泄的作用，本研究测试了输注I-BR对Sprague-Dawley大鼠磷酸盐排泄的影响。在甲状旁腺切除的Sprague-Dawley大鼠中，以0.8 ml/min的速度全身输注10 mM草酸I-p-溴四咪唑（I-BR，n = 6）或无活性异构体草酸d-p-溴四咪唑（d-BR，n = 5）之前和期间，测量磷酸盐的分数排泄（FEPi）。响应I-BR，FEPi从4.7%±0.9%显著增加至13.4%±3.1%，而无活性的d-BR对FEPi无影响。总之，全身输注I-p-溴四咪唑可增加Sprague-Dawley大鼠的FEPi。
