A³¹P Nuclear Magnetic Resonancein vivoStudy of Cerebral Ischaemia in the Gerbil

Abstract

Summary:We have used the noninvasive method of "'phosphorus nuclear magnetic resonance C'P N MR) in \'il'O to follow changes in phosphorous me tabolite concentrations and the intracellular pH in the right and left hemi spheres and in the cerebellum of gerbil brains after the occlusion of the right carotid artery, Spatial resolution over the brain was possible using surface coils. Ligation, which is known to cause ischaemia in this species in the ipsilat eral hemisphere, resulted in the diminution of phosphocreatine and adenine nucleotides and a decrease in tissue pH. Less acidification occurred in the contralateral hemisphere and in the cerebellum. The high-energy metabolite concentrations, phosphocreatine and adenosine triphosphate (ATP), declined in unison in the ischaemic region, in marked contrast to the sequence of events in skeletal muscle, in which phosphocreatine buffers against an immediate fall in ATP concentration. In a separate series of gerbils, 31p NMR spectra were followed for exactly 1 h after carotid ligation. The animals were then sacrificed and brain grey matter specific gravity was rapidly measured to assess the development of oedema. There was a clear correlation between abnormality of spectra and the presence of oedema. It cannot, however, be confidently as serted that a normal spectrum is never seen in oedematous gerbil brains. 3' P NMR spectra specific gravity and histological changes shown by light micros copy have been correlated and show that useful signals are received from a depth of at least 4 mm or more from the lO-mm diameter coil.

Changes in brain phosphorus metabolites during the post‐natal development of the rat.

“…The spectra from human infant brains differed from those found previously for animal brains (e.g. Ackerman et al 1980;Thulborn, Boulay, Duchen & Radda, 1982) in that the PCr peak was smaller and the most prominent peak in infant brain spectra, which was in the phosphomonoester (PME) region, was rather small and insignificant in the animal brain spectra. These differences could be related to species or to age.…”

Phosphorylation of chicken brain‐type creatine kinase affects a physiologically important kinetic parameter and gives rise to protein microheterogeneity in vivo

“…The importance of CP as a relevant physiological parameter is stressed by the fact, that the CP concentration of brain decreases during hypoxia or seizures without significant changes in ATP-levels [35]. Only if in addition the blood flow is decreased, CP and ATP levels fall towards zero rather quickly [36]. These data indicate that regional and possibly also subcellular fluctuations of CP levels can occur in brain.…”

Acute Cerebral Ischaemia: Concurrent Changes in Cerebral Blood Flow, Energy Metabolites, pH, and Lactate Measured with Hydrogen Clearance and31P and1H Nuclear Magnetic Resonance Spectroscopy. II. Changes during Ischaemia

“…In addition, earlier NMR studies have shown a corre lation between abnormality of spectra and the pres ence of oedema in the gerbil brain (Thulborn et al, 1982). Again, it is probable that the water accumu lation is a consequence of the energy failure.…”