Previous studies have defined separate and interactive effects of fetal plasma glucose (Gf) and insulin (If) concentrations on increasing fetal glucose utilization. To determine the role of glucose transporter proteins in enhancing net fetal tissue glucose uptake, we simultaneously measured fetal ovine glucose uptake and assessed the subcellular distribution of skeletal muscle Glut 1 (basal) and Glut 4 (insulin responsive) after “clamp” periods of 30-60 minutes, 2.5 hours, and 24 hours of selective hyperglycemia (↑G) or selective hyperinsulinemia(↑I). During the 2.5 hour period of ↑G, Gf increased from 20 to 39 mg/dl (p<0.01) without a change in If. In 2.5 hours of ↑I, If increased from 16 to 73 uU/ml (p<0.01) without a change in Gf. Under both study conditions, fetal glucose uptake increased, from 6.7 to 9.5 mg/min/kg (↑G) and from 7.5 to 11.4 mg/min/kg (↑I). Similar responses were observed at 30-60 minutes and 24 hours. Semi-quantitation of immunohistochemical analysis of hind limb skeletal muscle Glut 1 and Glut 4 revealed a sarcolemmal (SL) association of Glut 1 and an intracellular (IC) aggregation of Glut 4 at zero time. ↑G caused an 8-fold increase at 24 hours and ↑I caused a 4-fold increase at 30-60 minutes in the number of cells showing an SL association of Glut 1. In contrast, neither ↑G or ↑I altered the SL association of Glut 4 at any of the three time points. We conclude that high glucose and insulin concentrations independently translocate fetal ovine Glut 1 to the SL in a time dependent fashion, while not affecting Glut 4 translocation. Under both conditions, translocation of Glut 1 may contribute toward increasing net fetal glucose uptake.