Renin, kallikrein and angiotensin converting enzyme in human physical loading

The authors studied the correlation between the activity of renin, angiotensin-converting enzyme, the activity of prekallikrein and the blood prekallikrein level in men performing veloergometric exercise. At the same time they recorded the hemodynamic parameters (systolic and diastolic arterial pressure, the systolic rate, stroke volume and cardiac index, specific peripheral resistance). The blood samples collected before and immediately after the exercise showed a 41.4%-increase in the activity of renin and a 95%-increase in that of kallikrein, whereas the level of prekallikrein and the activity of the converting enzyme declined by 19 and 13% (P less than 0.05). These changes were accompanied by an increase in the systolic rate (by 107%) and in the systolic arterial pressure (by 36.7%), as well as by a reduction of the specific peripheral resistance (by 41.4%).