We describe enzymic fluorometric methods of automated analysis for glucose, lactate, pyruvate, 3-hydroxybutyrate, glycerol, and alanine in perchloric acid extracts of blood. Unmodified Technicon AutoAnalyzer II apparatus is used. The usual concentrations of all these metabolites can be measured in as little as 0.1 ml of blood from a fasting subject. Within-batch and between-batch coefficients of variation ranged from 0.4 to 4.4% for all metabolites except 3-hydroxybutyrate, for which CV's were higher for low concentrations. Analytical recovery of added metabolites ranged from 92 to 98%. Glucose, lactate, alanine, and 3-hydroxybutyrate are stable in perchloric acid extracts for at least 13 days at room temperature, and a year at -20 degrees C; pyruvate shows a 6--8% loss after 3 days and 52% by one year at -20 degrees C; glycerol concentrations were stable at -20 degrees C for at least 13 days. Blank fluorescence is found in perchloric acid extracts of blood, necessitating blank runs for pyruvate, 3-hydroxybutyrate, glycerol, and alanine. The systems are simple to use, relatively inexpensive to operate, and are recommended for any laboratory with high throughput of samples.

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The serum immunoreactive insulin response to an oral glucose load was estimated in 15 Asian Indian and 29 European non-diabetic subjects, and in 45 Asian Indian and 72 European Type 2 (non-insulin-dependent) diabetic patients. In the non-diabetic group, basal insulin values were higher in the Asian Indians than the Europeans (16.7 +/- 3.0 vs. 6.9 +/- 0.7 mU/l, p less than 0.001), and remained higher throughout the glucose tolerance test. Total insulin response was also higher in the Asian Indians (p less than 0.001), and linear regression analysis revealed basal insulin, body mass index and race to be important predictors of insulin response. Amongst the diabetic patients, basal insulin values were again higher in the Asian Indians compared with the Europeans (18.0 +/- 5.0 vs. 11.5 +/- 0.9 mU/l, p less than 0.05). Total insulin response was also greater (p less than 0.01). Linear regression analysis revealed the basal insulin value to be the only significant predictor of insulin response. The results demonstrate higher insulin levels in Asian Indians than Europeans in both normal subjects and Type 2 diabetic subjects. The insulin response to a glucose load is also greater in the Asian Indians. In the control subjects, ethnic differences contribute to this response, whereas in the diabetic patients this is a function of the elevated basal insulin values of the Asian Indians.

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The purpose of the present study was to examine the growth hormone (GH) response to treadmill sprinting in male (M) and female (F) sprint- and endurance-trained athletes. A group of 11 sprint-trained (ST; 6M, 5F) and 12 endurance-trained (ET; 6M, 6F) athletes performed a maximal 30-s sprint on a nonmotorized treadmill. Peak power and mean power expressed in watts or in watts per kilogram body mass were higher in ST than in ET (P < 0.01) and in the men compared to the women (P < 0.01). Serum GH was greater in ST than in ET athletes, but was not statistically significantly different between the men and the women [mean peak GH: ST 72.4 (SEM 12.5) compared to ET 26.3 (SEM 4.9) mU.1(-1), P < 0.01; men 59.8 (SEM 13.3) compared to the women 35.8 (SEM 7.4) mU.1(-1), n.s.]. Plasma ammonia and blood lactate concentrations were higher and blood pH lower during 1 h of recovery after the sprint in ST compared to ET (all P < 0.01). Multiple log linear regression showed that 82% of the variation in the serum peak GH response was explained by the peak power output and peak blood lactate response to the sprint. As serum GH was still approximately ten times the basal value in ST athletes after 1 h of recovery, it is suggested that the exercise-induced increase in GH could have important physiological effects in this group of athletes, including increased protein synthesis and sparing of protein degradation leading to maintained or increased muscle mass.