Six young healthy male subjects performed submaximal and maximal exercise on bicycle ergometers with one leg and two legs before and after 8 wk of one-leg training with each of both legs. The following variables were measured during one- and two-leg exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow, and iliac arteriovenous differences for oxygen and lactate. After training the maximal oxygen uptake during one- and two-leg exercise was increased by 19 and 11%, respectively. The corresponding cardiac outputs increased by 16 and 11%, respectively. During submaximal one-leg exercise, heart rate decreased by 11%, whereas a decrease of only 2% was seen during submaximal two-leg exercise. Mean blood pressure decreased by about 10 Torr in both types of exercise and during both submaximal and maximal exercise. Maximal leg blood flow increased only by 1.2 l/min during one-leg exercise. Leg blood flow and leg oxygen uptake were smaller during two-leg exercise than during one-leg exercise and more so after training. These findings indicate that one-leg exercise, compared with two-leg exercise, involves circulatory adaptations that respond differently to one-leg training. The findings further imply that oxygen supply to one large muscle group of exercising muscles may be limited by vasoconstriction when another large group of muscles is exercising simultaneously.

The present investigation was undertaken to study the kinetics of 99mTc-labelled diethylenetriaminepenta-acetate (DTPA) as compared with inulin and 51Cr-labelled ethylenediaminetetra-acetate (EDTA). Twenty patients with various degrees of decreased renal function were studied. The renal clearance, plasma clearance and volume of distribution of all three tracers were measured after a simultaneous single injection. The average renal clearance ratio 99mTc-DTPA to inulin was 0.97; the average renal clearance ratio 99mTc-DTPA to 51Cr-EDTA was 1.02. In all patients the plasma clearance of inulin exceeded that of 99mTc-DTPA. No difference was seen between the plasma clearance of 99mTc-DTPA and 51Cr-EDTA. The plasma clearance of all three tracers overestimated the simultaneously measured renal clearance; on average this was, for 99mTc-DTPA 5.7 ml/min, for 51Cr-EDTA 6.0 ml/min and for inulin 8.1 ml/min. The plasma clearance of 99mTc-DTPA correlated well with the renal clearance of inulin, but overestimated this by 3.5 ml/min on average. The volume of distribution of inulin was less than that of 99mTc-DTPA and 51Cr-EDTA. No difference was seen between the volume of distribution of 99mTc-DTPA and 51Cr-EDTA. It is concluded that the difference in the kinetics of 99mTc-DTPA and 51Cr-EDTA in patients with decreased renal function was small and without clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)

7 young, healthy, male subjects performed exercise on bicycle ergometers in two 20 min periods with an interval of 1 h. The first 10 min of each 20 min period consisted of arm exercise (38--62% of Vo2 max for arm exercise) or leg exercise (58--78% of Vo2 max for leg exercise). During the last 10 min the subjects performed combined arm and leg exercise (71--83% of Vo2 max for this type of exercise). The following variables were measured during each type of exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow (only during leg exercise and combined exercise), arterio-venous concentration differences for O2 and lactate at the levels of the axillary and the external iliac vessels. Superimposing a sufficiently strenuous arm exercise (oxygen uptake for arm exercise greater than 40% of oxygen uptake for combined exercise) on leg exercise caused a reduction in blood flow and oxygen uptake in the exercising legs with unchanged mean arterial blood pressure. Superimposing leg exercise on arm exercise caused a decrease in mean arterial blood pressure and an increased axillary arterio-venous oxygen difference. These findings indicate that the oxygen supply to one large group of exercising muscles may be limited by vasoconstriction or by a fall in arterial pressure, when another large group of muscles is exercising simultaneously.

increase in stroke volume or other central circulatory JENS TRAP-JENSEN. Central and peripheral circulatory changes after training of the arms or legs. Am.

The microvascular permeability to small and large molecules was studied during good and poor metabolic regulation in ten short duration juvenile diabetics. The following variables were measured; daily urinary albumin and beta2-microglobulin-excretion rates, whole body transcapillary escape rate of albumin (TER), glomerular filtration rate (GFR), capillary filtration coefficient (CFC), and capillary diffusion capacity (CDC). The urinary albumin and beta2-microglobulin concentration were measured by sensitive radioimmunoassays; TER was detemined from the initial disappearance of intravenously injected 125I-labelled human serum albumin; GFR was measured on the forearm by straingauge plethysmography and CDS for 51Cr-EDTA clearance; CFC was measured on the forearm by straingauge plethysmography and CDC, for 51Cr-EDTA was determined in the jyperaemic anterio tibial muscle by the local clearance technique. All the above mentioned variables, except CDC, were significantly increased during poor metabolic regulation, indicating a functional microangiopathy. The mechanisms of these alterations appear to be increased filtration pressure in the microcirculation and/or increased porosity of the microvasculature. The findings of increased microvascular albumin passage are compatible with the hypothesis that the organic - histologicallly demonstrated - diabetic microangiopathy is a long-term effect of periods of increased extravasation of plasma proteins, with subsequent protein deposition in the microvascular wall, i.e. the concept to plasmatic vasculosis.