Net protein synthesis and amino acid uptake with testosterone injection

Testosterone (T) administration is known to increase muscle size and lean body mass, especially when combined with exercise Thus, we hypothesized that T causes net protein synthesis and amino acid uptake. Five young males were studied before and 5 days after injection of 200mg of testosterone enanthate. Stable isotopes of phenylalanine and lysine were infused to determine net amino acid flux. In addition, muscle fractional synthetic (FSR) and …