Leukocytosis of exercise: role of cardiac output and catecholamines

Abstract

The effect of propranolol (5 mg iv) on the leukocytosis of exercise was studied in seven normal young males. Leukocyte counts, plasma norepinephrine (NE), epinephrine (E), and cardiac output were measured at rest and in the steady state of several submaximal work loads when subjects exercised on a cycle ergometer. The results in control experiments were compared with those obtained on a different day with propranolol. Propranolol decreased heart rate at all work loads (P less than 0.001) but had no effect on the increase in cardiac output at increasing work loads. Plasma NE and E levels were similar at rest and in exercise in control and propranolol studies. There was no effect of propranolol on the increase in leukocyte counts with increasing work loads. Although propranolol did not affect the increase in total leukocyte count, the increase in lymphocyte count at higher work loads was less with propranolol. We conclude that the demargination of leukocytes from the pulmonary circulation in exercise is probably a mechanical effect of the increase in cardiac output. However, we have not excluded a contribution from a humoral event that would decrease the adherence of leukocytes to endothelium during exercise. The smaller increase in lymphocytes at higher work loads in the presence of propranolol suggests that catecholamines affect the lymphocyte count over and above their effect on cardiac output.

Hot water immersion induces an acute cytokine response in cervical spinal cord injury

“…As repeatedly shown following exercise (Foster et al 1986;Laing et al 2008;Rhind et al 1999) and hyperthermia (Brenner et al 1999;Kappel et al 1998;Walsh and Whitham 2006) interventions in AB populations, we report increased neutrophil, lymphocyte and monocyte numbers following hot water immersion. While increased neutrophil counts have been observed earlier following exercise interventions in CSCI populations, lymphocyte numbers remained unchanged in this population (Kouda et al 2012;Yamanaka et al 2010).…”

“…It is possible that the different noradrenaline response between groups during immersion causes this first peak during immersion in lymphocyte numbers in AB. In line with this, blocking β-adrenergic receptors in AB (Foster et al 1986) has been demonstrated to reduce the post-exercise increase in lymphocyte numbers. Similarly, exercise in cold water to keep core temperature constant results in a blunted adrenaline response in AB, causing a reduced increase in lymphocyte numbers following exercise (Rhind et al 1999).…”

Activation and decreased deformability of neutrophils after intermittent claudication.

“…They may be attributed to recirculation of neutrophils from the ischemic leg and to the systemic effects of exercise on neutrophil kinetics. [27][28][29] In previous studies, local and global alterations in leukocyte deformability have been described in patients with peripheral arterial occlusive disease and chronic ischemia of the leg.20 The present study shows that local changes in neutrophil function and deformability immediately after claudication are more pronounced than global changes. Although the circulating pool of neutrophils only contains about 10% of the activated neutrophils, the arterial and venous blood difference in activated neutrophils immediately after claudication amounts to almost 50% of the total arterial and venous blood difference in neutrophils.…”

Wood smoke exposure induces a pulmonary and systemic inflammatory response in firefighters

“…It is known that vigorous exercise is associated with an increase in circulating white blood cells and PMN counts, largely due to mobilisation of these cells from the intravascular marginated pool by catecholamines [54]. In a subgroup of nine firefighters, an increase in circulating white blood cell and PMN counts, equivalent to those seen following smoke exposure, was induced by strenuous exercise without smoke exposure.…”