Age-dependent morphine partitioning between plasma and cerebrospinal fluid in monkeys.
Steady-state partitioning of morphine between blood and cerebrospinal fluid (CSF) was evaluated in pigtailed monkeys at three ages: 2-3 days, 1 month and 1 year. Protein binding of morphine to serum proteins was assessed by ultrafiltration. Newborns showed a higher CSF to plasma ratio than the 1-month- or 1-year-old monkeys (0.506 vs. 0.369 or 0.374, respectively). Protein binding of morphine was 11% in newborns, and 17% at 1 year of age, not explaining the increased morphine penetration into CSF in newborns. Increased CSF morphine is a transient finding in infant macaques, which appears to reach young adult values by 1 month of age.
Lynn
A M
AM
Department of Anesthesiology, School of Medicine, University of Washington, Seattle.
McRorie
T I
TI
Slattery
J T
JT
Calkins
D F
DF
Opheim
K E
KE
D000375:Aging / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001812:Blood-Brain Barrier / Q000502:physiology; D002490:Central Nervous System / Q000378:metabolism*; D006221:Halothane / Q000494:pharmacology; D007262:Infusions, Intravenous; D008254:Macaca nemestrina; D009020:Morphine / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*
D009020:Morphine; D006221:Halothane