Disease relevance of GLUT-1

• Thus maternal hyperglycemia causes a time-dependent decline in the entire placental glucose transporter pool (GLUT-1 and GLUT-3) [1].
• In contrast, selective hyperinsulinemia with euglycemia led to an immediate and persistent twofold increase in liver GLUT-1, which lasted from 1 until 24 h with a concomitant decline in myocardial tissue GLUT-4 amounts, reaching statistical significance at 24 h [2].
• We immunolocalized the GLUT-3 glucose transporter isoform versus GLUT-1 in the late-gestation epitheliochorial ovine placenta, and we examined the effect of chronic maternal hyperglycemia and hypoglycemia on placental GLUT-3 concentrations [1].
• We conclude that abnormal glucose concentrations alter rodent and ovine placental GLUT-1 levels in a time- and concentration-dependent manner; hypoxia may upregulate this effect [3].
• There was no effect of previous nutrient restriction on placental mass, fetal weight or GLUT-1 abundance at term, when ewes were well fed in the second half of gestation [4].

High impact information on GLUT-1

• We conclude that glucose exerts its effect on the macrophage, not on the bacterium, in the glucose-dependent nonopsonic phagocytosis of P. aeruginosa and that glucose transport via GLUT1 by the macrophages is required to trigger ingestion [5].
• The nucleotide sequence of the PCR product was identical to that published for murine GLUT1 [5].
• Cortisol treatment had no apparent effect on placental mRNA expression for the glucose transporters, GLUT-1 and GLUT-3 [6].
• Fructose-cultured PM phi developed fructose-dependent phagocytosis of P. aeruginosa with increased glucose-dependent phagocytosis, GLUT1 expression, and [14C]glucose transport [7].
• Phagocytosis by murine peritoneal macrophages (PM phi) of unopsonized Pseudomonas aeruginosa is a novel, glucose-dependent process occurring in concert with glucose or mannose transport via the GLUT1 facilitative transporter [7].

Chemical compound and disease context of GLUT-1

• This contrasts with the tissue-specific effects of selective hyperinsulinemia with a sustained increase in GURf associated with a sustained increase in hepatic basal glucose transporter (GLUT-1) amounts and a myocardial-specific emergence of mild insulin resistance associated with a downregulation of GLUT-4 [2].
• Thus high levels of cortisol such as occur after birth do not affect fetal cardiac myocyte binucleation or number but are associated with higher levels of ventricular Aogen mRNA, lower levels of Glut-1 mRNA, and hypertrophy of LVFW myocytes [8].

Biological context of GLUT-1

• GLUT1 and GLUT3 immunoreactivity was examined in fetal sheep brain sections of the frontal neocortex, caudate putamen and hippocampus at 0.73 gestation after fetal exposure to betamethasone by direct fetal intravenous infusion or maternal intramuscular injections at the clinically relevant dosage [9].
• These cellular adaptations in GLUT-1 (and GLUT-3) are geared toward protecting the conceptus from perturbations in substrate availability, and the adaptations in GLUT-4 are geared toward development of fetal insulin resistance [10].
• The changes in placental GLUT-1 concentrations may contribute toward the process of altered maternoplacentofetal transport of glucose, thereby regulating placental and fetal growth [3].
• Increasing maternal feed intake to meet calculated energy requirements in previously nutrient restricted ewes during the second half of gestation, increases placental mass and fetal weight, and the abundance of GLUT-1, an adaptation not observed if maternal food intake is increased above requirements [4].
• Nutritional treatment had no effect on the concentration of GLUT1 or GLUT4 in either tissue, and did not increase ovulation rate, despite increased concentrations of glucose and insulin [11].

Anatomical context of GLUT-1

• Glucose uptake into cerebral neurons is selectively facilitated by glucose transporter protein GLUT1 in the blood brain barrier and GLUT3 in neuronal membranes [9].
• GLUT-3 was limited to the apical surface of the trophoectoderm, whereas GLUT-1 was on the basolateral and apical surfaces of this cell layer and in the epithelial cells lining the placental uterine glands [1].
• The acute effect of selective hyperglycemia or hyperinsulinemia on late gestation fetal ovine glucose transporter protein (GLUT-1, GLUT-3, and GLUT-4) concentrations was examined in insulin-insensitive (brain and liver) and insulin-sensitive (myocardium and fat) tissues at 1, 2.5, and 24 h [2].
• Immunohistochemistry confirmed that GLUT-1 was located in the maternal uterine syncytium [4].
• The facilitative glucose transporter GLUT1 mRNA transcript was detected by PCR in preparations from purified macrophages [5].

Associations of GLUT-1 with chemical compounds

• Betamethasone did not alter GLUT1 and GLUT3 immunoreactivity in any of the brain regions investigated, independently of the dose and route of administration [9].

Analytical, diagnostic and therapeutic context of GLUT-1

• Only cavopulmonary anastomosis upregulated 2 stress-related genes, HO1 and GLUT1, 2.7-fold (P =.002) and 3.8-fold (P =.03), respectively [12].

References