L-alanine transport in isolated cells of interscapular brown adipose tissue in rat

The pattern of L-alanine uptake in isolated cells of interscapular brown adipose tissue has been determined. The uptake can be divided into the diffusion component (Kd=0.55 min⁻¹) and a saturable Na⁺-dependent transport (K_M=0.87 mM and V_max=155 nmol/min/10⁶ cells). The saturable component can be subdivided into MeAIB-sensitive (K_M=1.63 mM and V_max=162 nmol/min/10⁶ cells) and MeAIB-insensitive (K_M=3.2 mM and V_max=39.5 nmol/min/10⁶ cells). This kinetic pattern could indicate the presence of transport system (s) that resemble the commonly described transport systems for alanine uptake in several tissues.