Bioquímica cerebral
Effect of Verapamil Administration on Hypoxic Human Fetal Brain after Lactate detection by 1H Magnetic Resonance Spectroscopy (1HMRS)
Fecha de recepción: 31/12/2000
Fecha de aceptación:
31/12/2000
Abstract
The purpose of this study was to evaluate the effect of verapamil administration on Human Fetuses
in High Risk Pregnancies (FHRP) by Proton Magnetic Resonance Spectroscopy (1HMRS) after
Lactate identification. Two 1HMRS studies were performed on a 1.5 Tesla system using the body
RF coil: the first one was done between 30-31 weeks of gestation and the second between 34-35
weeks after verapamil administration. The results obtained in the second 1HMRS study show a
significant decrease in Lactate signal in FHRP compared with the first study. This reduction could
be related to a more oxygen availability due to the verapamil vasodilator effect in FHRP.
Key Word
Proton Magnetic Resonance Spectroscopy, Fetal Brain, Lactate, Hypoxia, Verapamil.
Introduction
The major cause of perinatal brain injury is the acute cerebral hypoxia-ischemia, which mostly occurs by impaired intrapartum gas exchange (1). Cerebral hypoxia in the fetus and newborn increase neonatal morbidity and mortality (2). The most frequently sequelae are mental retardation, cerebral palsy, seizure disorders (1-2), and attention deficit disorder (3) among others. 1HMRS allows noninvasive observations of cerebral Lactate (Lac), Creatine and phosphocreatine (Cr), Choline (Cho) and N-Acetylaspartate (NAA) in newborn infants with and without hypoxic-ischemic brain injury (4-9). Previous investigators have provided data suggesting that Lac is undetectable in the normal neonatal brain at term, but may be found in the brains of both preterm infants and infants who are small for his gestational age (5). 1HMRS is recognized as a noninvasive approach to monitor the human fetal brain since 1994 (10), and has been successful in detecting Lac on lambs fetal brain (11-12) and newborn piglet (15) during hypoxia. In a previous research (14-15), we reported Lac on the Brains of Human Fetuses in High Risk Pregnancies (FHRP) by 1HMRS which brought the possibility of prediction intrauterine hypoxia before the labor. The purpose of the present work was to evaluate the ability of vasodilator to reduce Lac upon administration to mothers with special emphasis on the improvement of the anaerobic pathway observed in FHRP.
Abbreviations:
1HMRS: Proton Magnetic Resonance Spectroscopy
MRI: Magnetic Resonance Imaging
Cho: Choline
Cr: Creatine and phosphocreatine
NAA: N-Acetylaspartate
Lac: Lactate
TE: Echo time
TR: Repetition time
RF: Radiofrequency
VOI: Volume of interest
FHRP: Human Fetuses in High Risk Pregnancies
Pi: inorganic phosphorus
ATP: Adenosine Triphosphate
Acknowledgements:
Physicians (Radiologists): H. Ortíz, M. Torcat, G. Zapata.
Anaesthetics: L.Díaz, M. Alliegro, J. Yungano, J. Morales.
MRI & MRS technicians: A. Guitan, J.Guitan, F. Paseta, A. Robaina, N. Isava, R. Cedeño, E. Contreras and M.V. Itriago.
Secretarial assistance: Y. Nazal, R. Velásquez, Y. Soares (CAIBCO)
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