The aims were to test whether 2 weeks treatment with the β 2 -adrenoceptor agonist, salbutamol, or the α 1 -adrenoceptor antagonist, doxazosin, could correct nerve blood flow and conduction velocity deficits in 8 week streptozotocin-diabetic rats and to examine neurovascular mechanisms using co-treatment with the nitric oxide synthase inhibitor, N G -nitro-l-arginine. Sciatic motor conduction velocity, 20.3% reduced by diabetes, was corrected by 88.2 and 88.5% for salbutamol and doxazosin, respectively. A 47.6% diabetic deficit in sciatic nutritive endoneurial blood, was substantially reversed by salbutamol (117.0%) and doxazosin (61.0%) treatment. The effects of α 1 -adrenoceptor blockade and β 2 -adrenoceptor stimulation on nerve blood flow and conduction velocity were almost completely (76.7-91.7%) attenuated by N G -nitro-l-arginine co-treatment. Thus, the data stress the importance of vasa nervorum α 1 and β 2 adrenoceptors and the permissive role of nitric oxide in nerve blood flow control mechanisms. They also indicate that β 2 -adrenoceptor agonists may be suitable for clinical trials of diabetic neuropathy.