Effects of elevated plasma magnesium concentration on cerebrospinal fluid levels of magnesium in neonatal swine.
To determine whether magnesium (Mg) can cross the blood brain barrier in developing swine, simultaneous measurements of [Mg] in plasma and cerebrospinal fluid (CSF) were made during experimental elevation of plasma [Mg] in 12 swine of differing postnatal age. All were anesthetized with Saffan and maintained at normal arterial blood gas composition. Aortic pressure and heart rate were monitored. Plasma and CSF samples, drawn at the beginning and end of a 60-min intravenous infusion of MgCl2 in all animals and every 10 min during the infusion in three, were analyzed for [Mg] and osmolality. CSF [Mg] increased in all animals as plasma [Mg] increased. There were no changes in CSF osmolality. The differences between plasma and CSF [Mg] was smallest in the youngest animals. These results indicate that Mg crosses the blood brain barrier in neonatal swine and suggest that the blood brain barrier is still maturing within the first postnatal month.
Rivera
L I
LI
Department of Pediatrics, Schneider Children's Hospital of the Long Island Jewish Medical Center, New Hyde Park, New York 11042.
Gootman
P M
PM
Lin
R H
RH
Gootman
N
N
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001812:Blood-Brain Barrier; D007262:Infusions, Intravenous; D008274:Magnesium / Q000008:administration & dosage / Q000097:blood* / Q000134:cerebrospinal fluid; D009994:Osmolar Concentration; D013552:Swine
D008274:Magnesium