Permeability of lactating-rat mammary gland Golgi membranes to monosaccharides.
The Golgi-membrane vesicles present in particulate preparations of lactating rat mammary gland were biosynthetically loaded with [14C]lactose. This lactose was effectively retained by particles sedimented after exposure to 0.25 M-disaccharide, but was partly lost after exposure to 0.25 M-glucose or other solutes of similar size. Loss of lactose was time-, concentration- and temperature-dependent and varied with the solute structure. This behaviour is ascribed to the presence of protein in the Golgi membrane, forming a specific carrier or channel that serves to supply glucose for lactose synthesis.
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D004187:Disaccharides / Q000494:pharmacology; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007774:Lactation; D007785:Lactose / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism*; D009996:Osmotic Fragility / Q000187:drug effects; D011247:Pregnancy; D051381:Rats
D004187:Disaccharides; D005947:Glucose; D007785:Lactose