Effect of glucosamine on A) glucose; B) pyruvate; C) lactate and D) palmitate oxidation.

<p>^* P<0.05 vs. 0 mM glucosamine, one-way ANOVA with Dunnett's posthoc test. 0 mM (n = 6), 0.05 mM (n = 4), 0.1 mM (n = 5), 5 mM (n = 5), 10 mM (n = 4).</p

Effect of glucosamine on A, B) Overall cardiac O-GlcNAc levels; C) UDP-HexNAc concentrations and D) ATP concentrations.

<p>^* P<0.05 vs. 0 mM, one-way ANOVA with Dunnett's posthoc test. Western blots: 0 mM (n = 8), 0.05 mM (n = 5), 0.1 mM (n = 9), 1 mM (n = 4), 5 mM (n = 8), 10 mM (n = 7). HPLC: 0 mM (n = 4), 0.05 mM (n = 5), 0.1 mM (n = 5), 1 mM (n = 4), 5 mM (n = 3), 10 mM (n = 3). Note that equal protein loading for the O-GlcNAc immunoblots was assessed by Sypro staining and overall O-GlcNAc levels were normalized to untreated control group.</p

Cardiac function of isolated rat hearts perfused with 0 (n = 8), 0.05 (n = 5), 0.1 (n = 10), 1 (n = 4), 5 (n = 8) and 10 mM (n = 7) glucosamine for 60 minutes (hearts were paced at 320 beats/min rate).

<p>Glucosamine had no effect either on cardiac or on coronary flow. (RPP: rate pressure product = left ventricular developed pressure×heart rate; dp/dt: change of pressure over time).</p

A) Immunoblots of Plasma membrane fraction for FAT/CD36 following 60 min perfusion with 0, 0.05, 0.1, 1, 5 and 10 mM; pan-cadherin included as a plasma membrane marker and protein loading control; B) Densitometric analysis of FAT/CD36 immunoblots normalized to 0 mM glucosamine; P<0.05 vs. 0 mM, one-way ANOVA with Dunnett's posthoc test; <i>n = 2 in each group</i>; C) Immunoprecipitation of FAT/CD36 from whole tissue and plasma membrane lysates, followed by O-GlcNAc and OGT immunoblots.

<p>Specificity of O-GlcNAc antibody was confirmed by co-incubation with 10 mM N-acetylglucosamine (GlcNAc).</p

Effect of 0.1 mM glucosamine on A) unlabeled glycolytic lactate efflux and B) exogenous [3-¹³C]lactate uptake ^* P<0.05 vs. 0 mM, Student's t-test.

<p>0 mM (n = 4), 0.1 mM (n = 5).</p