Plasma levels of renin, angiotensin II, and 6-ketoprostaglandin F1 alpha in endurance athletes.

Twelve male runners and 12 matched nonathletes performed a prolonged uninterrupted graded exercise test on the bicycle ergometer up to exhaustion to study blood pressure and plasma levels of renin (PRA), vasoconstrictor angiotensin II (ANG II), and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), a metabolite of the vasodilator prostacyclin. In the athletes work load was increased by 30 W/4 min, and in the control subjects the increments of work load were adjusted to their lower exercise capacity to equalize total exercise duration. Blood was drawn, and blood pressure and O2 uptake (VO2) were measured at rest and at the fourth, eighth, and last steps of exercise.

Active and acid-activable inactive renin during inhibition by indomethacin of prostaglandin synthesis in sodium-replete man.

The effect of inhibition of prostaglandin synthesis by indomethacin on active renin and on acid-activable inactive renin was studied in nine healthy, sodium-replete men, both at rest and exercise. These volunteers were investigated after pretreatment with placebo or indomethacin, 150 mg daily for 3 days. Indomethacin induced a decrease in active (P = 0.

Carotid baroreflex sensitivity and physical fitness in cycling tourists.

Carotid baroreceptors were stimulated with neck suction in 47 healthy subjects. Pulse interval lengthening was measured and the time course of the response was evaluated. Eight intensities of neck chamber suction were applied to select a criterion for computing the "RR response" that gives a significant linear relationship with the magnitude of the stimuli in the highest number of individuals.

The effects of beta blockers on exercise capacity and on training response in elderly subjects.

Treatment of 8 hypertensive elderly subjects with atenolol or with labetalol did not affect exercise performance, except after the development of circulatory congestion in 1 patient. Treatment with beta blockers did not alter the response to an exercise training programme in 15 elderly patients with ischaemic heart disease, as compared with 11 patients without such treatment.

Systolic time intervals in coronary heart disease at rest and during exercise: effect of physical training with and without beta blockade.

Systolic time intervals (STIs) were measured in recumbency at rest and in the sitting position at rest and during exercise, before and after a physical training program, in 28 patients with coronary heart disease. Fifteen patients were treated with a beta-blocking drug and 13 were not. After training, oxygen uptake at peak exercise increased similarly in both groups, by 41% and 37%, respectively, whereas heart rate at rest and during submaximal exercise decreased in both groups.

Changes in systolic time intervals during physical training in patients with ischemic heart disease. Effect of beta-blockade.

Systolic time intervals (STI) were measured at rest before and after an exercise training programme in 37 patients with ischemic heart disease; 17 patients were treated with a beta-blocking drug (BB-group) and 20 were not (nBB-group). After the training period peak oxygen uptake had increased by 37% in the BB-patients and by 41% in the nBB-group. During the training period electromechanical systole (QS2) and pre-ejection period (PEP), when corrected for heart rate, shortened significantly in all 37 patients.

Effects of tibalosine, a new alpha-adrenoceptor antagonist, in essential hypertension.

Tibalosine is a phenylethylamine derivative known to lower arterial pressure in hypertensive animal models. In a double-blind cross-over study, 12 patients with essential hypertension, on a constant sodium intake, received placebo and tibalosine, 150 mg daily. Standing (-5.