Type II diabetes accentuates diaphragm blood flow increases during submaximal exercise in the rat

Abstract

We investigated the effect of type 2 diabetes mellitus (T2DM) on respiratory muscle blood flow (BF) during exercise. Using the Goto-Kakizaki (GK) rat model of T2DM, we hypothesized that diaphragm, intercostal and transverse abdominis BFs (radiolabeled microspheres) would be higher in male GK rats (n=10) compared to healthy male Wistar controls (CON; n=8) during submaximal exercise (20 m/min, 10% grade). Blood glucose was significantly higher in GK (246±29 mg/dL) compared to CON (103±4 mg/dL; P<0.01). Respiratory muscle BFs were not different at rest (P>0.50). From rest to submaximal exercise, respiratory muscle BFs increased in both groups to all muscles (P<0.01). During submaximal exercise GK rats had higher diaphragm BFs (GK: 189±13; CON: 138±14 mL/min/100g, P<0.01), and vascular conductance (GK: 1.4±0.1; CON: 1.0±0.1 ml/min/mmHg/100g; P<0.01) compared to CON. There were no differences in intercostal or transverse abdominis BF or VC during exercise (P>0.15). These findings suggest that submaximal exercise requires a higher diaphragm BF and VC in T2DM compared to healthy counterparts.