Cotter M A, Cameron N E
Department of Biomedical Sciences, University of Aberdeen, Marischal College, Scotland, UK.
Naunyn Schmiedebergs Arch Pharmacol. 1995 Jun;351(6):630-5. doi: 10.1007/BF00170163.
The effects of carvedilol (10 mg kg-1 day-1), a peripheral vasodilator and oxygen free radical scavenger, on nerve conduction and blood flow were examined in streptozotocin-diabetic rats. Rats were treated from induction of diabetes for 1 month in a preventive experiment; effects of treatment in non-diabetic rats were also examined. Diabetes caused a 20.0% (P < 0.001) reduction in sciatic motor conduction and a 14.7% (P < 0.001) deficit in saphenous sensory conduction. Diabetic rats given carvedilol treatment had motor and sensory conduction velocities which did not differ significantly from those of non-diabetic controls, but were greater than for untreated diabetes (P < 0.001). Carvedilol treatment did not significantly alter nerve conduction in non-diabetic rats. The nutritive (capillary) component of sciatic endoneurial blood flow, measured by microelectrode polarography and hydrogen clearance, was 45.8% (P < 0.001) reduced by diabetes. This was completely corrected (P < 0.001) by carvedilol treatment in diabetic rats, flow being in the upper half of the non-diabetic range. In non-diabetic rats, carvedilol caused a 30.6% (P < 0.05) elevation in blood flow. Hydrogen clearance data also revealed a shift away from non-nutritive (arterio-venous anastomotic) towards nutritive flow in treated diabetic rats (P < 0.05). We conclude that the data support a neurovascular hypothesis of diabetic neuropathy. Carvedilol, via vasodilator and anti-oxidant actions, prevents the nutritive blood flow changes that lead to nerve dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)
在链脲佐菌素诱导的糖尿病大鼠中，研究了外周血管扩张剂及氧自由基清除剂卡维地洛（10毫克/千克/天）对神经传导和血流的影响。在一项预防性实验中，大鼠自糖尿病诱导起接受治疗1个月；同时也研究了卡维地洛对非糖尿病大鼠的治疗效果。糖尿病导致坐骨神经运动传导降低20.0%（P<0.001），隐神经感觉传导缺损14.7%（P<0.001）。接受卡维地洛治疗的糖尿病大鼠，其运动和感觉传导速度与非糖尿病对照组相比无显著差异，但高于未治疗的糖尿病大鼠（P<0.001）。卡维地洛治疗未显著改变非糖尿病大鼠的神经传导。通过微电极极谱法和氢清除法测量，糖尿病使坐骨神经内膜营养性（毛细血管）血流降低45.8%（P<0.001）。在糖尿病大鼠中，卡维地洛治疗可完全纠正这一情况（P<0.001），血流处于非糖尿病范围的上半部分。在非糖尿病大鼠中，卡维地洛使血流升高30.6%（P<0.05）。氢清除数据还显示，接受治疗的糖尿病大鼠的血流从非营养性（动静脉吻合）向营养性血流转变（P<0.05）。我们得出结论，这些数据支持糖尿病神经病变的神经血管假说。卡维地洛通过血管扩张和抗氧化作用，防止了导致神经功能障碍的营养性血流变化。（摘要截断于250字）
