Structural specificity of sugar transport at the blood-nerve barrier.

The major component of D-glucose transfer across the membranous sites of the blood-nerve barrier (BNB) occurs via a facilitative mechanism at a rate greater than twice the rate of D-glucose metabolism by nerve. To characterize further properties of monosaccharide transport at the BNB, unidirectional transfer constant (K) values were determined in vivo in tibial nerve of anesthetized rats for radiolabeled mannitol, L-glucose, and a series of D-glucose analogs. K values(X 10(-4) mls-1 g-1) equaled 4.

A compartmental analysis of solute transfer and exchange across blood-nerve barrier.

A three-compartment model was derived to analyze solute exchange among plasma, peripheral nerve epineurium, and endoneurium. The model was fit to measured tibial-nerve epineurial and endoneurial contents of [14C]sucrose after intravenous bolus injection of tracer in pentobarbital sodium-anesthetized rats. The transfer constant (K) for tracer at epineurial vessels approximated 1.

Sciatic nerve blood flow response to carbon dioxide.

Sciatic nerve blood flow (NBF) during hypercarbia was examined in unanesthetized decerebrate rats by means of laser Doppler flowmetry (LDF). During inspiration of gas mixtures containing no CO2, followed by either 5, 10 or 20% CO2, arterial pCO2 increased by 13, 18 and 68 mm Hg, respectively. Blood pressure (BP) and the LDF signal, which were measured continuously, increased for 30-40 s following the start of inhalation of CO2 and then decreased.

Permeability changes in blood-retinal barrier of galactosemic rats are prevented by aldose reductase inhibitors.

Permeability-surface-area products (PA) for sucrose at the blood-retinal barrier (BRB) were determined with quantitative in vivo techniques and compared in control rats, rats fed a 50% galactosemic diet, and rats fed a diet containing both galactose and the aldose reductase inhibitor sorbinil. The mean PA +/- SE for controls was 0.656 x 10(-5) +/- 0.