AJP - Regulatory, Integrative and Comparative Physiology, Vol 261, Issue 4 939-R944, Copyright © 1991 by American Physiological Society
Ultradian variations of chromogranin A in humans
M. A. Takiyyuddin, H. P. Neumann, J. H. Cervenka, B. Kennedy, T. Q. Dinh, M. G. Ziegler, A. D. Baron and D. T. O'Connor
Department of Medicine, University of California, San Diego.
Chromogranin A (CgA) is an acidic soluble protein exocytotically released
from virtually all neuroendocrine secretory vesicles. Here we examined
spontaneous variations in CgA and catecholamine concentrations in humans.
In normal subjects, basal CgA showed no day-to-day, week-to-week, or
diurnal variability. Plasma CgA had significant ultradian variation in
normotensives and hypertensives, and in bilaterally adrenalectomized
subjects. Gender, but not age or blood pressure, influenced CgA variations,
males having fewer (P less than 0.05) peaks per 8 h. Plasma catecholamines
had significant ultradian variations in both controls and bilaterally
adrenalectomized subjects. Within individuals, neither basal nor peak
plasma CgA correlated with catecholamines, nor was there concordance
between plasma CgA and catecholamine peaks. Somatostatin, a widespread
inhibitor of nonsympathoadrenal neuroendocrine secretion, diminished both
the frequency and amplitude of plasma CgA peaks. Thus spontaneous
variations in basal CgA are not directly linked to alterations in
sympathoadrenal catecholamine secretion. Furthermore, neuroendocrine
secretion at sites other than the sympathoadrenal system contributes to
spontaneous variations in CgA concentration.
