Expression and localisation of GLUT1 and GLUT12 glucose transporters in the pregnant and lactating rat mammary gland.
Glucose plays a major role in mammary gland function during lactation as it is used both as a fuel and as a precursor of milk components. In rats, previous studies have shown that the facilitative glucose transporter GLUT1 is expressed in mammary epithelial cells. We have used confocal immunofluorescence to localise GLUT1 and GLUT12, a recently identified member of the sugar transporter family, in pregnant and lactating rat mammary gland. GLUT12 staining was observed in the cytoplasm of mammary epithelial cells at day 20 of pregnancy, and at 1 and 6 days postpartum. Furthermore, GLUT12 staining was present at the apical plasma membrane of epithelial cells during lactation. In contrast, GLUT1 protein localised to the cytoplasm and basolateral surface of mammary epithelial cells. Forced weaning resulted in decreased cytoplasmic GLUT1 staining intensity, but no change in GLUT12 staining. The results suggest a possible role for GLUT12 in the metabolism of mammary epithelial cells during pregnancy and lactation.
Macheda
Maria L
ML
Department of Medicine, St. Vincent's Hospital, University of Melbourne, PO Box 2900, Fitzroy, Victoria 3065, Australia.
Williams
Elizabeth D
ED
Best
James D
JD
Wlodek
Mary E
ME
Rogers
Suzanne
S
D000818:Animals; D015153:Blotting, Western; D005260:Female; D005455:Fluorescent Antibody Technique; D005947:Glucose / Q000378:metabolism; D051246:Glucose Transport Proteins, Facilitative; D051272:Glucose Transporter Type 1; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000737:chemistry* / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000032:analysis* / Q000378:metabolism; D011247:Pregnancy; D051381:Rats
D051246:Glucose Transport Proteins, Facilitative; D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C449579:SLC2A12 protein, human; C495679:Slc2a1 protein, rat; D005947:Glucose