title: Axoplasmic transport of noradrenaline in the sciatic nerves of spontaneously diabetic mice.
abstract: The intraaxonal transport of noradrenaline and tyrosine hydroxylase was studied in the sciatic nerves of diabetic, obese and appropriate control mice. Noradrenaline and tyrosine hydroxylase accumulated proximal to a constriction applied to the nerves. Noradrenaline concentration in the non-constricted sciatic nerves did not differ significantly in nondiabetic and diabetic mice (0.67 +/- 0.04 and 0.58 +/- 0.01 ng/cm respectively); in obese mice and lean littermates the noradrenaline concentration was 0.47 +/- 0.05 ng/cm and 0.46 +/- 0.01 ng/cm. After nine hours of constriction the concentration of noradrenaline increased in the axons of nondiabetic (1.15 +/- 0.06 ng/cm), in obese (0.90 +/- 0.08 ng/cm) and lean mice (1.10 +/- 0.07 ng/cm) but remained low (0.68 +/- 0.07 ng/cm) in diabetic mice.--Administration of insulin (10 U/kg/day) to diabetic mutants completely reversed the decrease in NA accumulation. NA accumulated only in the nerve segment proximal (1 cm) to a constriction and was transported distally at an apparent velocity of 0.75 mm/hr in control axons. The difference of NA accumulation between diabetic and nondiabetic control indicate a reduced rate of axoplasmic flow in the noradrenergic axons of diabetic animals.
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D008297:Male; D051379:Mice; D008820:Mice, Obese; D009638:Norepinephrine / Q000378:metabolism*; D012584:Sciatic Nerve / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D014446:Tyrosine 3-Monooxygenase; D009638:Norepinephrine