title: Facilitated diffusion of monosaccharides in smooth muscle of rat vas deferens in vitro.
abstract: The suitability of rat vas deferens for investigating sugar transport in smooth muscle was determined in vitro, with the nonmetabolized glucose analog 3-O-methyl-D-glucose as test sugar. Vas deferens smooth muscle contains a facilitated diffusion system for monosaccharides, as shown by saturation of the transport sites and by competition between 3-O-methyl-D-glucose and D-glucose. The activity of the facilitated diffusion system could be enhanced by hyperosmolarity and by contractile activity, but frequency dependency could not be established. A high concentration of insulin (100 mU/mL) was required to stimulate sugar transport. As smooth muscle is not a primary tissue for the storage of energy reserves, it does not require large numbers of insulin receptors.
mesh_terms: D000818:Animals; D004058:Diffusion; D005110:Extracellular Space / Q000378:metabolism; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009005:Monosaccharides / Q000378:metabolism*; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000378:metabolism*; D051381:Rats; D014649:Vas Deferens / Q000378:metabolism
chemical_list: D007328:Insulin; D009005:Monosaccharides