Cerebral blood flow regulation in neonatal rabbits is altered by chronic cocaine administration

Abstract

Maternal cocaine abuse has several deleterious effects in the newborn, including perinatal asphyxia, hypoxia, and hypercapnia. We hypothesized that chronic cocaine exposure during development may alter cerebral blood flow (CBF) regulation. We studied 16 neonatal rabbits that had received cocaine (20 mg/kg, i.p. b.i.d.) or saline since birth. Changes in CBF were measured by laser doppler flowmetry before (baseline), and during hypercapnia (FiCO 2 = 7.5%), hypoxia (FiO 2 = 12%), and asphyxia (apnea for 1 min). During hypercapnia, CBF increased less in cocaine than in control animals (28 + 3% vs. 69 ± 10%, P < 0.05). During hypoxia, CBF increased similarly in both groups. During reventilation after asphyxia, CBF increased more in cocaine than in control animals (391 + 52% vs. 225 ± 43%, P < 0.05). Chronic cocaine exposure during brain development appears to alter CBF regulation to hypercapnia and asphyxia, which may put the drug exposed newborn at risk for neurologic injury around birth.