Regulation of NPY mRNA expression in primary cultures by these differentiating factors suggests that the expression of NPY mRNA in pheochromocytoma tissues may be associated with the neuronal differentiation of the tumor cells affected by multiple factors.
The renin-angiotensin system may, therefore, contribute to the secretion of catecholamines and NPY occurring in patients with pheochromocytoma and when stimulated trigger hypertensive crisis.
These data suggest that the determination of neuropeptide Y expression in the evaluation of patients with pheochromocytoma may have prognostic significance.