Figure 4.

Simplified schematic of neural, hormonal, redox, and immune signaling pathways activated in adrenal chromaffin cells. Intracellular signals may be integrated to regulate synthesis and secretion of CAs by chromaffin cells during normal or pathological conditions. Chromaffin cells are responsive to extracellular signaling molecules in the adrenal such as glucocorticoid, cytokines, and neurotransmitters. Sympathetic neurons release neuroactive molecules including both small molecule neurotransmitters (e.g., ACh and ATP) and peptide neurotransmitters (e.g., PACAP and substance P). Dashed line represents signaling mechanism supported by unpublished findings. Ach, Acetylcholine; PACAP, Pituitary Adenylate Cyclase-Activating Peptide; AC, Adenylyl Cyclase; CA, Catecholamine; GR, Glucocorticoid Receptor; HSP, Heat Shock Protein; NPY, Neuropeptide Y; PKA, Protein Kinase A; NO, Nitric Oxide; PKC, Protein Kinase C; GC, Guanylyl Cyclase.