ISSN:
1440-1681
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
1. In order to investigate exercise-induced changes of β2-adrenoceptors on human leukocyte subsets, β-adrenoceptor density was determined as specific binding of [125I]-iodocyanopindolol to granulocytes, monocytes, B and T lymphocytes of six subjects immediately before and after exercise and after 30 min of rest.2. A 10 min graded bicycle exercise with a workload of 50–250 W caused a transient increase of granulocytes, monocytes, B and T cells of about 32, 43, 120 and 25%, respectively.3. While the number of β2-adrenoceptors in granulocytes remained unchanged, β-adrenoceptor densities in B cells, T cells and monocytes increased from pre-exercise mean values of 2730, 870 and 2400 binding sites/cell to 3500, 1230 and 3220 binding sites/cell, respectively, under physical stress. The rise in receptor numbers was accompanied by an enhanced isoprenaline-stimulated cyclic AMP formation in unfractionated mononuclear leukocytes (MNL) of about 26% as well as by a 2–3-fold increase in plasma catecholamine levels. Cell concentrations, β2-adrenoceptor numbers and adrenergic responsiveness returned to normal after 30 min rest.4. Administration of 60 mg prednisone 2 h before exercise resulted in granulocytosis and lymphopenia with a preponderant effect on the exercise-induced rise in B cells and monocytes. Corticosteroids showed no effect on stress-induced changes of β2-adrenoceptors and responsiveness.5. It is concluded that exercise-induced increases in β2-adrenoceptor density and adrenergic responsiveness of unfractionated MNL are caused by a release of receptor-enriched cells into the circulation, particularly of B lymphocytes and monocytes which carry the highest β2-adrenoceptor density.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1440-1681.1988.tb01007.x
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