Developmental loss of hypoxic chemosensitivity in rat adrenomedullary chromaffin cells.

1. We investigated whether adrenomedullary chromaffin cells (AMCs) derived from neonatal (postnatal day (P) 1-P2) and juvenile (P13-P20) rats, and maintained in short-term culture (1-3 days), express O2-chemoreceptive properties. 2. In whole-cell recordings, the majority (approximately 70%; n = 47) of neonatal AMCs were sensitive to hypoxia. Under voltage clamp, acute hypoxia (PO2 approximately 40 mmHg) suppressed voltage-dependent K+ current …