GLUT3 glucose transporter isoform in rat testis: localization, effect of diabetes mellitus, and comparison to human testis.
Facilitative hexose transporter expression was compared in rat and human testes. In rat testis, only GLUT1 and GLUT3 proteins were expressed. By contrast, human testis expressed GLUT1 and GLUT3 in addition to GLUT5. Immunocytochemical studies showed that GLUT3 was expressed in all cells of the seminiferous epithelium of rat testis, including sperm. In human testis, GLUT3 was expressed exclusively in cells juxtaposed to the lumen of the seminiferous tubule and ejaculate sperm, a pattern of expression that was identical to that of GLUT5. Induction of insulinopenic diabetes mellitus in the rat did not alter the levels or the distribution of GLUT3 protein or mRNA in the testis. Moreover insulin treatment of the diabetic rats did not produce changes in GLUT3 mRNA or protein levels. The results show that rat and human testis express the high-affinity glucose transporter GLUT3, which allows for the efficient uptake of glucose. In addition, the testis may be protected from changes in glucose transporter expression in experimental diabetes.
Burant
C F
CF
Department of Medicine, University of Chicago, Illinois 60637.
Davidson
N O
NO
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism*; D051274:Glucose Transporter Type 3; D006801:Humans; D007150:Immunohistochemistry; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012670:Seminiferous Epithelium / Q000737:chemistry; D013094:Spermatozoa / Q000737:chemistry; D013737:Testis / Q000737:chemistry*; D014018:Tissue Distribution
D051274:Glucose Transporter Type 3; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C495687:SLC2A3 protein, human; C495690:Slc2a3 protein, rat