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Human immune cells mediate catecholamine secretion from adrenal chromaffin cells
H J Lujan1, H L Mathews, R L Gamelli
1University of Health Sciences/The Chicago Medical School, Mount Sinai Hospital Medical Center, IL, USA.
Critical Care Medicine
|July 22, 1998
Summary
Human immune cells release factors that stimulate catecholamine secretion from adrenal cells, a process influenced by immune cell activation and steroid suppression. This immune-adrenal axis may play a role in critical illness.
Area of Science:
- Immunology
- Endocrinology
- Neuroscience
Background:
- The interaction between the immune and endocrine systems is crucial for maintaining homeostasis.
- Adrenomedullary chromaffin cells secrete catecholamines, vital hormones involved in the stress response.
- The role of immune cells in modulating catecholamine release is not fully understood.
Purpose of the Study:
- To investigate the capacity of human mononuclear cells to produce factors stimulating catecholamine secretion from adrenomedullary chromaffin cells.
- To identify conditions that enhance the production of these immune-derived factors.
- To compare immune cell-mediated catecholamine secretion with responses to known stimuli like interleukin (IL)-1, IL-2, and nicotinic agonists.
Main Methods:
- In vitro study utilizing human mononuclear cells and porcine chromaffin cells.
- Mononuclear cells were cultured, and their conditioned media were tested for catecholamine-releasing activity.
- Immune cell stimulation (phytohemagglutinin, mixed leukocyte reaction) and suppression (dexamethasone) were employed.
- Catecholamine secretion was measured via high-performance liquid chromatography with electrochemical detection.
Main Results:
- Human mononuclear cell conditioned media induced significant epinephrine and norepinephrine secretion from chromaffin cells (6.9% vs. 1.4% for control media, p < .05).
- Stimulation via mixed leukocyte reaction resulted in higher catecholamine release (16.6%) compared to single-donor media (6.9%, p < .001).
- Dexamethasone suppressed the release of bioactive products, while IL-1 and IL-2 did not significantly stimulate catecholamine secretion.
Conclusions:
- Human immune cells release non-neural factors that stimulate catecholamine release from adrenomedullary cells.
- Immune cell factor production is modulated by immunostimulation and steroid suppression.
- This immune-adrenal pathway may contribute to elevated circulating catecholamines during infection and critical illness.