Related Experiment Videos
Specificity studies of leukocytic catecholamine receptors
International Journal of Clinical Pharmacology and Biopharmacy
|April 1, 1978
Summary
Human leukocytes bind epinephrine, but this binding site is not the beta-adrenergic receptor. Further research is needed to determine the physiological role of this catecholamine binding in leukocytes.
Area of Science:
- Biochemistry
- Immunology
- Pharmacology
Background:
- Epinephrine (adrenaline) is known to bind to human leukocytes.
- The biological significance of this catecholamine binding requires further investigation.
Purpose of the Study:
- To assess the biological significance of epinephrine binding to human leukocytes.
- To compare the specificity of leukocyte binding with the inhibition of adenyl cyclase activity.
Main Methods:
- Utilized tritium-labeled dl(+/-)epinephrine to study binding.
- Compared catecholamine binding specificity with their ability to inhibit epinephrine-stimulated adenyl cyclase.
Main Results:
- Leukocyte binding is specific for catechols but does not differentiate between active/inactive stereoisomers or alpha/beta-adrenergic agonists.
- d(+)epinephrine exhibited noncompetitive inhibition of adenyl cyclase, indicating the binding site is not a beta-adrenergic receptor.
- Several compounds, including d(+)epinephrine, failed to stimulate leukocytic adenyl cyclase.
Conclusions:
- The catechol-binding site on human leukocytes is distinct from the beta-adrenergic receptor.
- The physiological relevance of this catecholamine binding to leukocytes remains undetermined.