Exercise-induced increase in glandular kallikrein activity in human plasma and its significance in peripheral glucose metabolism.

Glucose uptake into skeletal muscle of human forearm at rest and during exercise is reported to be diminished by the administration of a kallikrein (kallidinogenase) inhibitor. The present study was conducted to clarify the changes of glandular kallikrein (GK) activity in human plasma during acute exercise and its significance in peripheral glucose metabolism. 10 non-diabetic inpatients, aged 49.5 years, and 8 diabetic inpatients, aged 53.8 years, were studied. After an overnight fast, bicycle ergometer exercise test was performed for 15 min (25 W (5 min)----50 W (5 min)----75 W (5 min]. Before (basal), during (at 15 min) and after exercise (at 25 min), venous blood samples were drawn to determine plasma GK activity and glucose, serum immunoreactive insulin (IRI), C-peptide immunoreactivity (CPR), nonesterified fatty acids, pyruvate, lactate, noradrenaline and adrenaline levels. In the 1st trial, in both non-diabetics (n = 10) and diabetics (n = 8), plasma GK activity increased significantly during exercise. After the 1st trial, in 6 patients (5 non-diabetics; 1 diabetic), exercise test was repeated once after 2-4 weeks and in a diabetic patient, exercise test was repeated twice at 4-week intervals, accordingly exercise test was performed 26 times in 18 patients in total. Natural logarithmic correlation between sigma glucose level and sigma GK activity (r = 0.52, n = 26), and hyperbolic correlation between sigma glucose level and sigma IRI level (r = -0.66, n = 26) but no correlation between sigma glucose level and sigma CPR level (r = 0.17, n = 26) were found.(ABSTRACT TRUNCATED AT 250 WORDS)