Expression of glucose transporters in lactating human mammary gland epithelial cells.
BACKGROUND
Human milk contains 60-80 g/l lactose and and oligosaccharides. To synthesize this large amount of carbohydrates, the lactating mammary gland has a high demand for precursor molecules. such as glucose and galactose.


OBJECTIVE
In the present study we investigated the molecular basis for the uptake of glucose and galactose into the human mammary gland.


METHODS
Using RT-PCR, Southern and Western blotting we analyzed the expression of SGLT1 (sodium glucose cotransporter 1) und GLUT1 (sodium independent glucose transporter) in epithelial cells isolated from fresh human milk.


RESULTS
Southern blot analysis of the amplicions revealed the expression of SGLT1 mRNA but not of GLUT1 mRNA in milk epithelial cells. Using Western blotting, SGLT1 protein was identified in human milk cells. CONCLUSIONS. Our findings indicate that 1) the cell fraction isolated from fresh human milk is a suitable model for investigating gene expression in the human mammary gland and 2) lactating human mammary gland epithelial cells are supplied with monosaccharides mainly via SGLT1.
Obermeier
S
S
Forschungsinstitut für Kinderernährung, Dortmund, Germany.
Hüselweh
B
B
Tinel
H
H
Kinne
R H
RH
Kunz
C
C
D015139:Blotting, Southern; D015153:Blotting, Western; D001940:Breast / Q000166:cytology / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology; D005260:Female; D005690:Galactose / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D051272:Glucose Transporter Type 1; D006801:Humans; D007774:Lactation / Q000235:genetics / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008895:Milk, Human / Q000737:chemistry* / Q000166:cytology; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051269:Sodium-Glucose Transporter 1
D051272:Glucose Transporter Type 1; D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; C495677:SLC2A1 protein, human; C495674:SLC5A1 protein, human; D051269:Sodium-Glucose Transporter 1; D005947:Glucose; D005690:Galactose