3-O-methylglucose transport in soleus muscle of bacteremic rats

Basal and insulin-stimulated soleus muscle 3-O-[14C]methylglucose ([14C]-3-O-MG) transport was studied in vitro and in vivo during bacteremia in rats. Fasted rats were injected with Escherichia coli to produce bacteremia (B), and controls (C) received saline. In vitro studies using soleus muscles were carried out 8 or 12 h after bacterial injection, and transport was measured using the rate coefficient (lambda = min-1). Although insulin-stimulated (10 mU/ml) [14C]-3-O-MG transport was decreased in 12-h bacteremic rat muscles (lambda B = 0.041 +/- 0.003; lambda C = 0.055 +/- 0.002), the basal [14C]-3-O-MG transport rate coefficient was elevated (lambda B = 0.027 +/- 0.004; lambda C = 0.019 +/- 0.001). For in vivo studies, [14C]-3-O-MG with or without insulin was injected into rats 10-40 min prior to removing soleus muscles at 12 h postbacterial or postsaline injection. Transport was measured as the ratio of [14C]-3-O-MGintracell/[14C]-3-O-MGextracell. Basal ratios were not different and muscles from both control and bacteremic rats responded comparably to insulin with increased [14C]-3-O-MG transport during the initial 30 min. At 35-40 min postinsulin injection there was a further stimulation of [14C]-3-O-MG transport in control but not in 12-h bacteremic rat muscles. The changes in [14C]-3-O-MG transport observed in vitro and in vivo after 12 h of bacteremia may be due to circulating mediators and/or changes in membrane function.