Effect of acute exercise on plasma immunoreactive-atrial natriuretic factor

Area of Science:

• Exercise Physiology
• Endocrinology
• Cardiovascular Physiology

Background:

• Atrial natriuretic factor (ANF) plays a role in cardiovascular homeostasis.
• The impact of acute exercise intensity on ANF secretion requires further elucidation.

Purpose of the Study:

• To investigate the effect of graded acute exercise on plasma immunoreactive-atrial natriuretic factor (IR-ANF) levels.
• To examine the relationship between exercise intensity and the secretion of ANF, arginine-vasopressin (AVP), and aldosterone (ALDO).

Main Methods:

• Healthy young males underwent graded exercise on a bicycle ergometer at intensities ranging from 30% to 90% VO2max.
• Blood samples were collected during submaximal exercise (30 min) and at exhaustion.
• Plasma concentrations of IR-ANF, AVP, and ALDO were measured.

Main Results:

• Plasma IR-ANF increased significantly with exercise intensity, showing a dose-response relationship.
• Plasma AVP and ALDO concentrations rose significantly only at higher exercise intensities (70% and 90% VO2max) and at exhaustion.
• Hormonal responses were correlated with exercise intensity and the blood lactate threshold.

Conclusions:

• Acute exercise stimulates ANF secretion proportionally to exercise intensity.
• Elevated plasma AVP and ALDO during exercise are associated with workloads exceeding the blood lactate threshold.