Sharma, RKansal, V K2001-08-292009-05-272001-08-292009-05-272001-08-29Sharma R, Kansal VK. Heterogeneity of transport systems for L-glutamine in mouse mammary gland. Indian Journal of Biochemistry & Biophysics. 2001 Aug; 38(4): 241-8http://imsear.searo.who.int/handle/123456789/28281The characteristics of the transport systems of L-glutamine in lactating mouse mammary gland have been studied. L-glutamine uptake was mediated by three Na+-dependent and one Na+-independent systems. The 2-(methylamino)isobutyric acid-sensitive component of Na+-dependent uptake exhibited the usual characteristics of system A. The other two Na+-dependent systems, which we have named BCI(-)-dependent and BCl(-)-independent, are the new systems identified. These are broad specificity systems and were discriminated on the basis of inhibition analysis, Cl- dependency and the effect of preloading mammary tissue with amino acids. While L-aspargine inhibited the uptake of L-glutamine via both these broad specificity systems, L-homoserine inhibited the uptake of L-glutamine via only BCl(-)-dependent system. The uptake of L-glutamine via the BCl(-)-independent system was upregulated by preloading mammary tissue with L-serine, while BCl(-)-dependent system was unaffected. The Na+-independent uptake of L-glutamine was inhibited by 2-aminobicyclo-(2,2,1)heptane carboxylic acid and other neutral amino acids, and identified as the system L.engAmino Acids, Cyclic --pharmacologyAnimalsBiological Transport --drug effectsFemaleGlutamine --metabolismHydrogen-Ion ConcentrationKineticsLactation --physiologyMammary Glands, Animal --drug effectsMiceOrgan Culture TechniquesSodium --metabolismJournal Article