Chromogranin A (CGA), a large acidic 48-kD protein, costored and coreleased by exocytosis with catecholamines, has been shown to be a precursor of peptides that exert feedback regulatory control on catecholamine secretion. In plasma, CGA levels increase in response to a large-amplitude physical stimulation in adult subjects and may be related to catecholamine levels. Any akin information is not yet available when the sympathoadrenal system is highly actived during birth. This activation is strongly related to parturition circumstances such as the mode of delivery. The aim of our study was to determine CGA plasma levels in infants delivered vaginally or by elective cesarean section and to investigate the possible correlation between CGA and catecholamine concentrations. Plasma levels of catecholamines (norepinephrine and epinephrine) and CGA were assessed by HPLC with electrochemical detection and immunoenzymology, respectively. CGA and norepinephrine concentrations were significantly higher ( p < 0.0002 and p < 0.02) in infants vaginally born than in the group delivered by elective cesarean section. A significant relationship (p < 0.04) was found between CGA and norepinephrine levels. However, for epinephrine, no significant difference was found between both groups. These results demonstrate the fetus' ability to corelease CGA and norepinephrine massively in response to stress of birth. (Pediatr Res 37: [101][102][103][104][105] 1995)

We investigated the effects of prenatal exposure to dexamethasone on paraganglia and adrenal catecholamine stores in rabbit neonates. We compared pregnant rabbits injected with 0.01 mg x kg(-1) of dexamethasone (Dex) from day 24 to day 27 of gestation to an untreated group of unmanipulated rabbits. A group injected with 0.9% saline solution was added to evaluate the effect of injection and handling. Catecholamines were assessed by HPLC in offspring paraganglia and adrenal glands on days 0, 1, and 7 after birth. Data were analyzed by a two-factor ANOVA and Bonferroni-Dunn and t tests. Statistical significance was accepted at p < 0.05. Paraganglia catecholamine levels were significantly higher in the Dex animals than in the untreated ones at every maturational stage studied. For saline animals, the levels were lower than in the Dex group and higher than in the untreated one. In adrenal glands, the same pattern was observed for noradrenaline only. These findings suggest that such a treatment has a positive long-term effect on catecholamine levels of both structures with a more marked effect on paraganglia, an extra-adrenal structure exerting a main function during the perinatal period in providing the child with catecholamine stores.