Asthma pregnancy alters postnatal development of chromaffin cells in the rat adrenal medulla

Background

Adrenal neuroendocrine plays an important role in asthma. The activity of the sympathoadrenal system could be altered by early life events. The effects of maternal asthma during pregnancy on the adrenal medulla of offspring remain unknown.

Methodology/Principal Findings

This study aims to explore the influence of maternal asthma during pregnancy on the development and function of adrenal medulla in offspring from postnatal day 3 (P3) to postnatal day 60 (P60). Asthmatic pregnant rats (AP), nerve growth factor (NGF)-treated pregnant rats (NP) and NGF antibody-treated pregnant rats (ANP) were sensitized and challenged with ovalbumin (OVA); NP and ANP were treated with NGF and NGF antibody respectively. Offspring rats from the maternal group were divided into four groups: offspring from control pregnant rats (OCP), offspring from AP (OAP), offspring from NP (ONP), and offspring from ANP (OANP). The expressions of phenylethanolamine N-methyltransferase (PNMT) protein in adrenal medulla were analyzed. The concentrations of epinephrine (EPI), corticosterone and NGF in serum were measured. Adrenal medulla chromaffin cells (AMCC) were prone to differentiate into sympathetic nerve cells in OAP and ONP. Both EPI and PNMT were decreased in OAP from P3 to P14, and then reached normal level gradually from P30 to P60, which were lower from birth to adulthood in ONP. Corticosterone concentration increased significantly in OAP and ONP.

Conclusion/Significance

Asthma pregnancy may promote AMCC to differentiate into sympathetic neurons in offspring rats and inhibit the synthesis of EPI, resulting in dysfunction of bronchial relaxation.