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Biomedical subjects

W Erdmann

Publications and source records attributed to W Erdmann.

153 records · Page 9Linked to original sources

Effects of ischemia on the oxygen diffusion coefficients in the brain cortex (studies on Macaca irus).

In this series of experiments changes in oxygen diffusion coefficients were measured in waking primates undergoing focal middle cerebral artery ischemia; Ligation of the middle cerebral artery followed by a decrease of the oxygen diffusion coefficient in the areas supplied by that vessel to levels ten to twenty per cent below normal by twenty-five minutes following onset of ischemia. Following release and re-perfusion diffusion coefficient gradually increases and reaches a super normal peak value three hours after release of ligation. This is followed by a gradual reduction in diffusion coefficient with stabilization at preocclusion levels. In the three experiments described these changes following re-perfusion corresponded with clinical improvement of the neurological status of the monkeys;

Animals↗

Comparison of vascular reactivity in spinal cord and brain.

The local tissue PO2 in the brain cortex and in the spinal cord of rats was examined with ultramicroelectrodes. In the spinal cord the PO2 was highest in white matter, intermediate in dorsal horn gray matter, and lowest in the ventral horn gray matter. In the gray matter of the cord, as well as in the brain, the PO2 at a fixed locus was found normally to oscillate. CO2 responses were more brisk in the cord than in the brain while the responses to hypoxia were similar. Therefore, it appears that the physiological regulation of blood flow in the spinal cord is qualitatively similar to that of the brain.

Animals↗