Enhanced brain stem 5HT₂A receptor function under neonatal hypoxic insult: role of glucose, oxygen, and epinephrine resuscitation.

Molecular processes regulating brain stem serotonergic receptors play an important role in the control of respiration. We evaluated 5-HT(2A) receptor alterations in the brain stem of neonatal rats exposed to hypoxic insult and the effect of glucose, oxygen, and epinephrine resuscitation in ameliorating these alterations. Hypoxic stress increased the total 5-HT and 5-HT(2A) receptor number along with an up regulation of 5-HT Transporter and 5-HT(2A) receptor gene in the brain stem of neonates. These serotonergic alterations were reversed by glucose supplementation alone and along with oxygen to hypoxic neonates. The enhanced brain stem 5-HT(2A) receptors act as a modulator of ventilatory response to hypoxia, which can in turn result in pulmonary vasoconstriction and cognitive dysfunction. The adverse effects of 100% oxygenation and epinephrine administration to hypoxic neonates were also reported. This has immense clinical significance in neonatal care.