Glycolytic flux in permeabilized freshly isolated vascular smooth muscle cells

To determine whether channeling of glycolytic intermediates canoccur in vascular smooth muscle (VSM), we permeabilized freshly isolated VSM cells from hog carotid arteries with dextran sulfate. Thedextran sulfate-treated cells did not exclude trypan blue, a dye withmolecular weight of ~1,000. If glycolytic intermediates freelydiffuse, plasmalemmal permeabilization would allow intermediates toexit the cell and glycolytic flux should cease. We incubated permeabilized and nonpermeabilized cells with 5 mM1-¹³C]glucose at37°C for 3 h. ¹³C nuclearmagnetic resonance (NMR) was used to determine relative 3-¹³C]lactateproduction and to identify any¹³C-labeled glycolyticintermediates that exited from the permeabilized cells.3-¹³C]lactateproduction from1-¹³C]glucose wasdecreased by an average of 32% (n = 6) in permeabilized cells compared with intact cells. No¹³C-labeled glycolyticintermediates were observed in the bathing solution of permeabilizedcells. We conclude that channeling of glycolytic intermediates canoccur in VSM cells.