Minimal influence of blood flow on interstitial glucose and lactate-normal and insulin-resistant muscle. Holm[umlaut]ang, A., M. M[umlaut]uller, O. K. Andersson, P. L[diaeresis]onnroth. The Wallenberg Laboratory, Department of Heart and Lung Diseases, G[diaeresis]oteborg University, G[diaeresis]oteborg, Sweden. Department of Clinical Pharmacology, Vienna University Hospital, Vienna, Austria. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, G[diaeresis]oteborg University, G[diaeresis]oteborg, Sweden
APStracts 4:0263E, 1997.
To study the regulation of the interstitial glucose concentration in skeletal muscle, nine control subjects and nine older and overweight NIDDM subjects with extreme insulin resistance were investigated with microdialysis in the medial femoral muscle before and during a euglycemic insulin clamp. After fasting over night, arterial plasma glucose was 4.9+/-0.1 and 8.5+/-0.6 mmol/l (p<0.001). The arterial -interstitial concentration (A-I) differences of glucose and lactate were 0.43+/-0.16 mmol/l (p<0.05) and -0.13+/-0.05 mmol/l, respectively, in normals. In NIDDM subjects, (A-I) differences for glucose and lactate were non-significant. Muscle blood flow was similar in controls and NIDDM subjects. During the glucose clamp the glucose (A-I) differences increased and the lactate (A-I) differences decreased significantly in both groups. The glucose 170 infusion rate was 8.0+/-0.77 mg/kg/min vs 3.2+/-0.51 mg/kg/min (p<0.001) and blood flow 9.9+/-1.6 ml/100g/min vs 6.7+/-0.9 ml/100 g/min (p<0.05) in controls and NIDDM subjects, respectively. These results show that 1. the capillary wall is rate limiting for muscle glucose uptake and lactate release in control subjects but not in postabsorptive hyperglycemic insulin-resistant subjects, 2. vasodilation during insulin infusion does not prevent the increase in arterial -interstitial (A-I) difference of glucose in normal subjects and 3. in severely insulin-resistant muscle, the (A-I) difference of glucose is not extended despite lack of vasodilation.

Received 14 July 1997; accepted in final form 12 November 1997.
APS Manuscript Number E330-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 December 1997